MOBILE CELL PHONE CHARGER CIRCUIT SCHEMATIC DIAGRAM

 The main part of the circuit mobile cellphone charger is timer IC NE555, used to charge and monitor the voltage level. IC1 get control voltage to pin 5 by zener diode ZD1­. Threshold pin 6 and trigger pin 2 is supplied with a voltage set by VR1 and VR2 respectively. The trigger pin 2 of IC1 is below 1/3VCC when discharge battery is connected to the circuit as a result flip-flop of IC1 is switched on to take output pin 3 high. The process is reversed when battery is fully charged of charged battery is connected. Here transistor T1 used to enhance the charging current from output pin 3 of IC1. Adjust potentiometer VR1 and VR2 as per require.

LED status for different charging conditions

Load across the output	Output frequency (at pin 3)	LED1
No battery connected	765 kHz	On
Charging battery	4.5 Hz	Blink
Fully charged battery	0	Off

Circuit Diagram

Parts
Resistors (all ¼-watt, ± 5% Carbon)
R1 = 390 Ω
R2 = 680 Ω

R₃ = 39 Ω/1W

R₄ = 27 KΩ

R₅ = 47 KΩ

R₆ = 3.3 KΩ

R₇ = 100 Ω/1W

VR₁, VR₂ = 20 KΩ

Capacitors
C1 = 0.001 µF (ceramic disc)
C2 = 0.01 µF (ceramic disc)
C3 = 4.7 µF/25V (Electrolytic )

Semiconductors
IC1 = NE555 timer IC
T1 = SL100 or any Medium power general purpose NPN transistor like: 2N4922 , 2N4921,2N4238, FCX1053A
ZD1 = 5.6 V/1W
LED1
Miscellaneous 
SW1 = On/off switch
1.5V*8 AA cells
Mobile connector

Source- http://electronicsproject.org/mobile-cellphone-charger/

BATTERY CHARGER WITH BUILT IN PROTECTION CIRCUIT DIAGRAM

IT  is a circuit for a battery charger with automatic overload protection feature.  

The power supply is 9V and is stabilized by a voltage regulator IC LM317.  

The regulator output is used to charge the 6V battery.  

Once the battery is fully charged (ie the voltage across the battery is 6V) enters the zener diode biased and starts conducting, which gives a positive voltage to the base terminal of BC548  loading.

 Battery Charger with Protection Circuit Diagram

KURZWEIL SP2X MUSICAL INSTRUMENT - HOW TO ENTER THE BOOT BLOCK, HOW TO REPLACE THE BATTERY, HOW TO REMOVE THE KEYBOARD ASSEMBLY, HARD RESET PROCEDURE

 

HARD RESET

There are two ways to perform a Hard Reset to the SP2X.

Press the Global button and press the Reset button segment displays following screen  and press + button segment displays an message. Press the + button again segment finally displays to    continue or the Yes or No button.

Software Updates

A computer with a MIDI interface and sequencer is necessary to transfer software to your SP2X units MIDI Sysex.

File Formats

Software upgrades are stored as standard MIDI files. Filenames are in the format SP2XVV.MID, where X is the software block and VVV is the version number (V.VV). The following lists the possible values for X. Never install files with names that don’t conform to this format; it won’t work.

bk—boot block for keyboard models

k—operating system software for keyboard models.

Installing the Operating System or Setups

Warning: This procedure requires performing a hard reset. All user programs and setups will be erased. Before continuing, be sure to save all user programs and setups.

1. Connect a MIDI cable from the MIDI Out port of the computer interface or sequencer to the MIDI In port on the PC2.

2. Open the first .MID file using the sequencer program.

3. Turn on the SP2X and follow the procedure to enter the Boot Block.

4. Press the Enter button to select “uOS”

5. The segment shows “uOS”. Start playing the MIDI file from the sequencer. While a file is loading, the bottom line of the display shows the progress. If the display continues to show after starting the sequencer, stop and restart the sequence.

6. After the file is loaded, the display will show “oK”.

7. If you have additional files to load, open the file from the sequencer and begin playing it.

8. Press the Cancel button twice to return to the main menu. Scroll to Hard Reset and select.

Installing a New Boot Block

Warning: This procedure performs a hard reset. All user programs and setups will be erased.  Before continuing, be sure to save all user programs and setups.

1. Connect a MIDI cable from the MIDI Out port of the computer interface or sequencer to the MIDI In port on the SP2X.

2. Using the sequencer program, open the first .MID file.

3. Turn on the SP2X and follow the procedure to enter the Boot Block.

4. Press the Enter button to select . 6. The segment shows . Start playing the MIDI file from the sequencer. While a file is loading, the bottom line of the display shows the progress. If the display continues to show  after starting the sequencer, stop and restart the sequence.

7. After the file is loaded, the unit will reset.

Replacing the Battery

The SP2X uses a flat three volt Lithium coin cell battery.  When the battery voltage runs low, the unit boots up with a low battery message.

Note: The battery voltage can be checked at anytime using the Scanner Diagnostics.

Accessing the Battery

1. Place the SP2X upside down on a flat protected surface.

2. Remove top assembly and set it safely aside.

Removing the Battery

The battery (CR2032) in the SP2X is mounted into a holder on the Engine Board and is accessible when the access panel is removed.

1.    Insert a flat plastic tool (plastic knife, pen cap, etc.) into one of the openings between the battery and the holder to lift the battery. 

2.    2. Ease the battery out of the holder. If necessary, insert the plastic tool at the bottom of the holder (closest to the Engine Board) to remove the battery.

Installing the Battery

1.    Position the battery over the holder so that the positive terminal is pointing to the Engine Board.

2.    2. Slide the battery into the holder and apply slight pressure until it snaps into place.

3.    4. Install the seven screws to secure the top assembly

SP2X Scanner Test

The Scanner Tests for the SP2X include separate tests for the front panel buttons and LEDs, front panel knobs including the Master Volume slider, the Mod and Pitch wheels, the keyboard, and the pedals.

To enter the Scanner Tests, first turn on the SP2X. Once the SP2X is on and ready to play, simultaneously hold down the Main, Layer and Split buttons. All front panel LEDs will flash and the segment will display the following:

Segment example, SP2X scanner tests

“SP2”, “SCn”, then “vX.Y” are displayed briefly in sequence vX.Y means version of the scanner installed the unit.

“bAt” means “Battery” and the voltage is X.Y volts. Normal battery voltage is around 3.0 volts where 3.2v is typical for a new battery and less than 2.8 means the battery is nearing the end of its life and has only a few months left. At 2.2 volts, warning will begin. A completely dead oe missing battery may not read exactly 0.0v but will certainly read less than 1.0v.

Next “PCH” then “XXX” is displayed in sequence. “PCH” means the Pitch(left) Wheel and XXX is its centre reading at power‐on. Ideally this is 128 but anything between 120 and 136 is acceptable. New units should be adjusted to be between 126 and 130 to allow for drift over the life of the unit.

Last is a display of which option diodes have been installed. First “jPr” is displayed briefly then 4 vertical lines will show briefly. Each line represents an option diode from Opt1(leftmost) to Opt4(rightmost) A long line(2 segments long) mans the corresponding diode is installed while a short line(1 segment) is not installed. Option settings normally tell the scanner software the keyboard length and weight and should match the actual unit.

Front Panel Buttons

When a button is pressed, its LED(if any) turns on and its matrix address is shown in the display. Each press of Knob Mode will right the next Knob Mode LED in a top down sequences. Rhythm and Program button has two color led, each button press, RED and GREEN LEDs turns on alternatively.

Front Panel Knobs

When a knob or the volume slider is moved, its name is shown briefly then its changing value is displayed. The names are

“vol” – volume slider,

“KnA” – Knob A,

“Knb” – Knob B,

“KnC” – Knob C,

“Knd” – Knob D.

The name should be correct and the value numbers should run smoothly from 0(or 1) up to 255(254) as slider moved upward or the knob clockwise. When turned very slowly, the number display will typically change in steps of two(1,3,5,,or 2,4,6,,,,) and may even switch from even to 30 .

Keyboard Problems

Odd and back which is normal.  Big jumps of more than 3 counts which turning slowly may indicate a problem.  However, When the control is released, its last reading should remain without changing by more than 2 counts.

Keyboard

When a keyboard key is pressed, the key’s musical pitch should be shown in the display. The first character should be the note name .The second character should be blank for white keys or a “high o(sharp sign) for black keys. The third character should be the octave number from 0 to 8.  Thus Middle C will be shown as “C 4”

Besides the key name, the 3 decimal points in the display reveal important information about the rubber switches under the key being pressed. When the key is pressed partially, the left decimal point will indicate that the first rubber switch and made contact. When the key is pressed further, the middle decimal point indicates that the key is pressed further, the middle decimal points indicates that the second rubber switch has also made contact. Thus when a key is pressed slowly, the following sequence should be observed exactly 0.

Blank Display ‐> Correct Key name and left decimal point ‐> Correctly Key name and left and centre decimal points If the correct key name and only the centre decimal point lights, then there is a defect associated with the first switch. If all 3 decimal points light, then either more than one key is processing at

once or there is a short circuit in the connecting or on the connector.

Switch Pedals

If a single switch pedal is plugged into the SW jack, operating it should case a response in the display.   For Kurzweil pedals, pressing the pedal should cause “S1C” to be displayed while releasing it should cause “S1o” to be displayed.  Other vender’s pedals may cause the opposite response. If a dual pedal is plugged in, then the Sustain (right) pedal should display as described above. The Soft pedal (left) should cause “S2C” and “S2o” to display. As with the buttons, the display should respond immediately and without flickering if pedal working properly.

Continuous Pedals

If control pedal is plugged into the CC jack, operating it should cause the display to show “CP1” briefly then its changing values. As with the volume slide r and knobs, the value display should smoothly increase from 0 to 1 up to 254 or 255 as the pedal is pressed. This is the ideal range of a perfectly calibrated Kurzweil pedal. Many pedals may only reach 248‐250 which acceptable. All should go down to 0 or 1 however.

Removing the SP2X Keyboard Assembly

The following procedure assumes that the SP2X is open and that you have followed the instructions to remove the top enclosure.

1. The keyboard is secured to the bottom enclosure using nine screws. Refer to Figure  for the position of the screws. Arrows identify the locations of the nine screws.

2. Tilt the SP2X up and remove the five keyboard rear screws, then lay the SP2X flat on your work surface.

3. Move the SP2X forward so that the front hangs over the edge of your work surface to access the remaining screws, and remove the five keyboard front screws.

4. Remove the four Mod Wheel screws and washers. At this point the keyboard is loose in the bottom enclosure, but it has cables connected to the Mod Wheel Assembly and the Connector Board.

In some cases, tape secures cable connections or fastens cables to the bottom enclosure. Always peel back the tape from one side when disconnecting cables so that the tape remains properly positioned.

The removal and replacement of surface‐mount devices requires training and the proper equipment. If you do not have the training or equipment to remove or replace surface‐mount devices, contact the service department to order a board replacement. International service technicians should contact their appropriate Young Chang Distributor.

Saving User Data

1. Set up a MIDI recording device.

2. Connect the a MIDI cable to the MIDI Out port of the SP2X to the MIDI In port on the external device.

3. Press the Global button on the SP2X. Press the +/‐ cursor button until the segment displays 

4. Begin recording on the MIDI recording device.

5. Press Rythm on the SP2X. The segment shows

When all objects are saved, will appear in the display.

6. To reload the saved objects, connect a MIDI cable from the MIDI Out port of the recording device to the SP2X’s MIDI In port.

7. From the external device, begin the playback of the file.

Entering the Boot Block

Use the SP2X’s Boot Loader to enter Diagnostics or perform a Hard Reset to the unit. You can also install operating system updates and ROM objects into Flash ROM.

Apply power to the unit. When the  message appears in the display, quickly press and release the Transpose button. The segment displays the main menu of the Boot Loader and the first available option. Use the + or – button to advance to the next option.

The menu options are as follows:

Install Engine  — Installs new operating system software upgrades.

Update Boot block  — Installs boot block updates.

Run Diagnostics   — enters the diagnostic test menu. For a complete list of tests and the procedure to execute the diagnostic tests.

Run Engine    — Exits the boot block and returns the unit to normal operation.

Hard RESET  — Clears the memory to factory default settings.

UNIVERSAL CHARGER FOR LEAD-ACID BATTERIES 12V, 1 ... 30AH

A device for charging small lead-acid (gel) batteries. The design has a number of very valuable functions that are rarely found in other chargers. First of all, it is that the device prevents overcharging the battery. When the battery is charged, the charge current automatically decreases. If a 230 V mains failure occurs during charging, the device will not discharge the battery. The charger can work as a power source.  12v, 1...30Аh

Characteristic
 charging 12 V lead acid batteries
 battery capacity: 1 ... 30 Ah
 charging system alarm: two-color LED diode
 sound signal of wrong polarity
 power source: 11 ... 13 V (the power of the transformer should be at least 50% than the power obtained by multiplying the charging current and voltage of 15 V)

Circuit description
The device is used to charge small lead-acid batteries. The device can also work with the battery as a buffer power source, providing uninterrupted power to devices.





The presented circuit has a number of very valuable functions rarely found in chargers. Primarily:
 Prevents battery overcharging. When the battery is fully charged, the charging current drops to a negligible value, so even multi-day charging is not terrible.

 Loss of mains voltage during charging will not lead to a rapid discharge of the battery - then the discharge current is about 2.5 mA.
 The charger is not afraid of reverse battery connection. Most chargers with a reverse battery connection can be damaged by the huge current flowing through the output circuits.
 The circuit is also not afraid of a short circuit of the output terminals of the charger.
 A two-color LED indicates the operating status, and smooth changes from red to green reflect the charging process.
All these functions are implemented in a very simple scheme containing several popular and cheap elements.
Pay attention to the correct soldering of the terminals of the buzzer Y1, which is designed to work with a battery connected in the opposite direction. The charging current should be selected depending on the capacity of the rechargeable battery. It is very easy. It is necessary to solder 1-ohm resistors (indicated on the RS circuit) to obtain the necessary current. One RS resistor with a value of 1 Ω provides a charging current of approximately 0.15 A. For example, for a 2 Ah gel cell, the maximum charging current is 0.6 A (0.3 · 2), so you need to solder four RS resistors per 1 Ohm. After assembling and checking the entire battery, connect the battery to terminals P, N. When charging a discharged battery, the current on it will be immediately large, but after a while it will stabilize to a value determined by the active resistance PR1. Use potentiometer PR1 to adjust the final charge voltage. If the charger will operate in uninterrupted power mode (constantly on and connected to the battery), then PR1 should set the final voltage to about 13.8 V (13.5 ... 13.8 V), which corresponds to a value of 2.25 ... 2.3 In per element, guaranteeing the expected durability. During cyclic operation (alternate charging and discharging), the final voltage on the battery should be about 15 V (14.4 ... 15 V). This voltage value is not critical here. The higher the voltage, the faster the battery will charge. However, leaving the battery continuously under a voltage of more than 15 V. can shorten its life. Soldering the corresponding number of RS resistors per 1 Ohm and setting the potentiometer PR1 are the only necessary settings.
For transistor T1, you need to choose the appropriate radiator. Its size will depend on the charging current and voltage of the transformer. At low currents, a piece of aluminum sheet may suffice. 12 1-ohm resistors will give a maximum current of 2A. For this, the radiator must be appropriate. During operation, such a radiator can be very hot - up to +90 ... 100 C. When choosing a charging current, remember that it should not exceed numerically 0.3 C (C is the battery capacity in ampere-hours). At 0.3 C, a full charge will be approximately 6 hours. For example, for a battery with a capacity of 10 ampere-hours (10 A · h), the charging current should not exceed 3 A (0.3 · 10 A · h). Some manufacturers give a maximum charging current of 0.25C. Of course, the charging current can be reduced to 0.1 C or even 0.05 C, but then the charging time will drastically increase, even up to tens of hours. The value of the charging current determines the resulting resistance of the resistors RS1 ... RS4.

The circuit diagram (Fig. 1) shows four RS resistors. Four groups are provided on the sample board to solder up to 12 resistors. This method was used intentionally because it makes it very easy to select a charging current. The power transformer used must have a nominal (alternating) voltage of 12 ... 15 V. Its power will depend on the required charging current. The power of the transformer must be at least 50% higher than the power obtained by multiplying the charging current and a voltage of 15 V. For example, for a charging current of 0.6 A, the product of 0.6 A · 15 V is 9 W, so the power of the transformer should not be less than 13.5 watts (150% * 9 watts).

Details

BATTERY VOLTAGE CHARGE STATUS LED

In [1], a diagram of a simple indicator of the state of a battery of batteries was presented. The author used it for a ship model, but the scope of this scheme, of course, can be much wider.
The main conditions for achieving long battery life are, in particular, limiting the maximum battery discharge current and the absence of deep
discharge. Even the simplest battery voltage indicator helps to fulfill the last condition (Fig . 1) .




The operation of the circuit is based on the use of the properties of the integral parametric voltage stabilizer D1 of type TL431 and its analogues (LM431, KA431, etc.). The fact is that at a voltage of less than 2.5 V (if the battery is discharged), the output transistor of the IC D1 is in a non-conductive state and the current flowing through this chip does not exceed 1 mA. The voltage drop across the resistor R3 (U e ) is small, and the transistor T1 is locked. Accordingly, the base current through the elements R5 unlocked transistor T2. A light on the D2 LED indicates that the device’s battery is low.
If the VT1 battery is in the working (charged) state, then at the control transition of the MS D1 the voltage reaches 2.5 V, and the output transistor of this microcircuit is unlocked. The current flowing through D1 and R3 will increase. The increase in current will lead to an increase in the voltage drop across the resistor R3 (U e ), the opening of the transistor T1 and the locking of the transistor T2. LED D2 is off.
Depending on the supply voltage of the VT1 source, a voltage threshold is set, below which the LED D2 begins to glow . The extinction voltage D2 in this circuit is made slightly higher than the beginning of the glow of D2. This is achieved by connecting the lower output circuit with the collector of the transistor T2, and not with the "minus" of the circuit power source.
To be able to more accurately set the moment of ignition of the indicator LED D 2, the author of the publication [1] recommends using Fig. 1 chain of tuning resistance R1.1 with a nominal value of 10 kOhm and a limiting resistor R1.2 with a nominal value of 10 kOhm.
In principle, instead of the integral parallel voltage regulator D1, a standard low-power zener diode can be used. Its type and stabilization voltage depend on the supply voltage of the circuit, or rather, on the rated voltage of the used VT1 battery.


Literature
 Wolfgang Fritz. Flat Battery Indicator // - 2015. - No. 7/8. - P.30-31.
Prepared by Andrey Nikolaev, Zaporozhye

HP ENVY 14 STEP BY STEP DISASSEMBLING PROCEDURE OF –– HOW TO REMOVE THE KEYBOARD – HOW TO REMOVE THE TOP COVER – HOW TO REMOVE THE BATTERY

Step by step disassembling procedure of  HP ENVY 14 –– How to remove the keyboard – How to remove the top cover – How to remove the battery

How to remove Battery

Before disassembling the computer, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
Remove the battery:
1. Slide the battery cover release latch (1). (The battery cover releases forward (2)).

2. Remove the battery cover. The battery cover is included in the Door Kit, spare part numbers 608384-001 (for use only with standard computer models) and 629879-001 (for use only with Beats Edition computer models)

3. Slide the right battery release latch (1) to unlock the battery.

4. Slide and hold the left battery release latch (2) to release the battery.
5. Pull the battery tab (3), and then remove the battery from the computer.

How to remove SIM

Before removing the SIM, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Remove the battery cover and battery
Remove the memory module:
1. Press in on the SIM (1) to release it from the SIM slot.
2. Remove the SIM (2) from the SIM slot.

How to remove Mass storage device

Before removing the mass storage device, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Remove the battery cover and battery

Remove the mass storage device:
1. Remove the four Phillips PM2.0×3.0 screws that secure the mass storage device to the computer.

2. Use the Mylar tab (1) to slide the mass storage device to the right and disconnect it from the system board.

3. Lift the mass storage device (2) out of the mass storage device bay.

How to remove WWAN module

Before removing the WWAN module, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Remove the battery cover and battery
5. Remove the hard drive
Remove the WWAN module:
1. Disconnect the WWAN antenna cables from the terminals on the WWAN module.

2. Remove the two Phillips PM2.0×3.0 screws that secure the WWAN module to the system board. (The WWAN module tilts up.)

3. Remove the WWAN module by pulling the module away from the slot at an angle.

How to remove RTC battery

Before removing the RTC battery, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Remove the battery cover and battery
5. Remove the memory module/wireless module compartment cover
Remove the RTC battery:
1. Disconnect the RTC battery cable from the system board.

2. Remove the RTC battery from the system board. The RTC battery is attached to the system board with double-sided tape.

How to remove Top cover

Before removing the top cover, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Remove the battery cover and battery
5. Remove the memory module/wireless module compartment cover
Remove the top cover:
1. Remove the eight Phillips PM2.5×7.0 screws that secure the top cover to the computer.

2. Remove the three Phillips PM2.0×3.0 screws that secure the top cover to the computer in the battery bay.

3. Turn the computer right side up, with the front toward you.

4. Open the computer as far as it will open.
5. Lift the front edge of top cover (1) until the TouchPad cable is accessible.
6. Release the ZIF connector to which the TouchPad cable is attached, and then disconnect the cable
(2) from the system board.

7. Slide the top cover (1) forward until the power button board cable, keyboard cable, and keyboard light cable are accessible.

8. Release the power button board cable (2) from the fan surface. (The power button board cable is attached to the fan surface with double-sided tape.)
9. Disconnect the power button board cable (3) from the system board.
10. Release the ZIF connector to which the keyboard light cable is attached, and then disconnect the
cable (4) from the system board.

11. Release the ZIF connector to which the keyboard cable is attached, and then disconnect the cable
(5) from the system board.

How to remove Keyboard

Before removing the keyboard, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Remove the battery cover and battery
5. Remove the memory module/wireless module compartment cover
6. Remove the top cover
Remove the keyboard:
1. Turn the top cover upside down, with the front toward you.
2. Press on the back of the keyboard (1) through the opening in the top cover until the keyboard disengages from the top cover.

3. Release the keyboard light cable (2) and the keyboard cable (3) through their respective openings in the top cover.

4. Turn the top cover and keyboard right-side up, with the front toward you.

5. Swing the rear edge of the keyboard (1) up and forward until it rests at an angle.
6. Slide the keyboard (2) back at an angle until the tabs on the front edge of keyboard disengage from the slots in the top cover

APPLE IPAD PRO 12.9 – SPECIFICATION - DISASSEMBLING PROCEDURE – BATTERY – COMPONENTS

Apple iPad Pro 12.9 – Specification - Disassembling procedure – Battery – Components

SPECIFICATION 

Apple iPad Pro 12.9 - Specification - Disassembling procedure - Components - Tablets repair and service.

1. Fully laminated, 12.9" Multi-Touch LCD with a 2,732 × 2,048 resolution at 264 ppi and antireflective coating
3rd generation 64-bit A9X chip paired with M9 motion coprocessor Self-balancing, four-speaker audio

2. 8-megapixel 1080p rear-facing iSight camera + 1.2-megapixel 720p front-facing FaceTime HD camera
3. 802.11a/​b/​g/​n/​ac MIMO Wi-Fi + Bluetooth 4.2
4. Touch ID fingerprint sensor + 3- axis gyro + accelerometer + barometer + ambient light sensor
5. 32 GB or 128 GB on-board storage

Peeking along the edge of the iPad, we spot a new accessory port - Apple's Smart Connector - making its debut appearance.
The Smart Connector supports Apple's own Smart Keyboard as well as third-party accessories that transfer power and data, like keyboards and docking stations.
On the bottom edge, two of the four speakers in the highly touted speaker array live on either side of a now-familiar Lightning Connector.

After a little heat-to-heat, with an opening picks and heavy duty suction cup to open the conversation.

DISASSEMBLING PROCEDURE
The Pro's display is packing the same adhesive as its smaller counterparts - it's tough and there's way too much - but it's still no match for our seasoned teardown hands.
With the adhesive finally out of the way, we get our first glimpse of the Pro's interior.

Now to remove that display

With the logic board situated in the center of the iPad, the display cables connect in the very middle of the device, so you can't even lay the display down while we work.
Instead, you first have to support the weight of the display while removing the screws that secure the display cable bracket.On the back of the display, you will find the following.

2 × Broadcom BCM15900B0
NXP Semiconductors 8416A1 Touch ID Sensor
Parade Technologies DP695 Timing Controller
Apple says this is an iteration of the DP665 LCD timing controller found in the iMac Retina
5K, modified to support the display's variable refresh rate.
Texas Instruments TPS65144 (Likely an iteration of the TPS65143A LCD Bias found in the Air 2)

A logic board relocation isn't the only easily-recognized layout difference between the iPad Pro and previous iPads. While the iPad Air 2's interior real estate was dominated by a proportionately  massive battery, the iPad Pro dedicates a significant amount of room to speaker enclosures.

It appears that the Pro's self-balancing, four-speaker audio comes at the cost of battery capacity. Based on our measurements, the speaker enclosures occupy about half as much space as the battery.
That's space that could have potentially been used for an extra 50% battery capacity. Its sure Apple was very careful setting the balance between battery capacity, weight, and sound quality.

Next,  lend a hand to the FaceTime HD (left) and iSight cameras, which are trapped behind a bracket.While just about everything in this tablet has been billed as bigger and better than previous  devices, these cameras seem to be the same as those found in the iPad Air 2.

For those of you keeping score: the rear-facing camera captures the same 8 MP images and 1080p video at 30 fps, while the front-facing selfie cam shoots identical 1.2 MP images and 720p video.

Here's a first in iPad history: we have to remove the logic board's EMI shielding to remove the logic board itself.

This shielding not only protects the logic board from interference, but also hides cable connectors and secures the logic board to the rear case.

As you continue to mine deeper into this iPad Pro, the next Balrog component you find is the headphone jack.

Just like the 3.5 mm jack in the iPad Air 2, the ribbon cable on this headphone jack harbors one of the Pro's two front-facing ambient light sensors.

Finally, you get to (one of) the highly anticipated self-balancing speaker drivers. Yes, speaker drivers. The whole speaker consists of the driver and its capped resonance chamber. 

Although these speakers share a common design, their function changes depending on the tablet's orientation. Whether in portrait or landscape mode, the Pro always sends higher frequencies to the topmost speakers to produce a more balanced sound.

The speakers are nice, but what makes them really sing are the fancy back volume chambers, machined directly into the unibody enclosure.

Apple claims that this new design provides up to three times more output than previous iPad models.
After removing the carbon fiber caps, you will find the enclosures are filled with foam. On Your way to the logic board, you stop to smell the flowers antennas.

Just like the iPad Air 2, the Pro's two antennas use MIMO technology to provide 802.11ac Wi-Fi speeds of up to 866 Mbps, and LTE speeds of up to 150 Mbps

There are just a few things left standing between us and the logic board.

A bit of deft spudgering frees the remaining speaker connectors, and a flex cable that appears to run beneath the left battery cell to drive the Smart Connector contacts.
At long last we've extracted the logic board - and its (sadly) soldered on Lightning connector

The logic board contains the following 

1. Apple APL1021 A9X 64-bit Processor

2.  SK Hynix H9HCNNNBTUMLNR-NLH 16 Gb (2 GB) LPDDR4 RAM (2 GB × 2 = 4 GB total)
3. Toshiba THGBX5G8D4KLDXG 32 GB NAND Flash
4. InvenSense MP67B 6-axis Gyroscope and Accelerometer Combo
5. NXP 65V10 NFC Controller (also found in the iPhone 6/6 Plus, as well as Nexus 5X and 6P marked NXP 54802)
6. NXP Semiconductors LPC11U37 ARM Cortex-M0 Microcontroller
7. Apple (Cirrus Logic) 338S1213 Audio Codec.

Even more chips on the logic board:

Fresco Logic FL1100SX 2-port USB 3.0 Host Controller
Universal Scientific Industrial 339S00045 Wi-Fi Module
NXP 1610A3 (also found in  iPhone 6s/6s Plus, likely an iteration of the 1610A1 found in the iPad Mini 4)
Dialog Semiconductor 343S00025-A1
Dialog Semiconductor 343S00052-A1
Maxim Integrated MAX98721CEWV (likely an iteration of the MAX98721BEWV found in the iPad Air 2)
Fairchild Semiconductor FDMC 6683 power management chipThese new pull tabs are even cooler than their iPhone counterparts; there's no need to worry about tweezer grip or stubby fingers - these tabs have a handy spudger hole.

You will  have so much fun pulling out these adhesive tabs that you thought you would include a video.

And unlike on iPhones where you only get two or three tabs to tug, the iPad Pro comes with eight.

Thanks to those pull tabs, the battery is freed with ease.

The iPad Pro's 3.77 V battery weighs in at an impressive 10307 mAh.
This prodigious, 38.8 Wh power source offers a 40 percent increase over the 27.62 Wh battery in the iPad Air 2, but just barely edges out the 38.2 Wh battery we found in the Surface Pro 4.The last component You will  try to remove on the road to teardown glory is the Smart Connector port cable.

JBL FLIP 2 – WIRELESS BLUETOOTH SPEAKER - HOW TO REPLACE THE BATTERY

JBL Flip 2 – Wireless Bluetooth Speaker - How to replace the battery

JBL Flip 2

Begin by removing the rubber caps on both sides of the JBL Flip 2 by using the black spudger to get in between the creases.
Be very careful when removing the nfc rubber cap. There is a chip that is glued to the inside of the rubber cap. So, peel the rubber cap off slowly and remove the chip on the inside while peeling the rubber cap off.

Using the driver adapter with the number 1 Philip's head bit, remove the eight 7.0 mm screws on both sides of the JBL Flip 2.

The nfc chip is glued onto the side of the device. Use the black spudger to separate the mic from the surface.

Be careful not to sever the wire connecting the nfc chip to the inside of the device.
Gently slide the nfc chip into the device through the slot that the wire comes from.

Peel the black rubber piece from one end to the other.

Remove the two 7.0 mm screws using the driver adapter with the #1 Philip's head bit.

Carefully detach the silver plastic cover by pulling both ends off.
Pull both ends at the same time with the same amount of force to prevent the cover from breaking.
Separate the silver plastic piece by pulling it off from the middle.

Using the driver adapter with the #3.0 flat-head bit, pry out the 8 metal nibs on the back side of the speaker.

Repeat the same process for the 4 remaining metal nibs (two on each end).

Expand the metal casing and carefully slide it off the speaker.

Using the driver adapter, first insert the #4 socket into the driver; followed by the #1

Philip's head bit in order to reach the three 13.0 mm screws.

Using the classic spudger, get underneath the black tape strips found on both side of the device.

After lifting a portion of the tape off of the device, gently peel the tape off of the device, making sure to keep it intact.
There is another piece of tape on the side of the device with the control buttons. Lift the tape with the classic spudger and then peel the rest of the tape off.

Wedge a spudger between the two halves where the tape was to pry the device open. When working with electronics, it's important to choose a tool that's ESD-safe to avoid accidental damage to the device. The regular black nylon spudger or a plastic opening tool should be used whenever possible

Use the black spudger to disconnect the speaker cord from it's socket.

Use the black spudger to disconnect the auxiliary wire from its socket.

Carefully remove the cable connecting the control chip to the motherboard.

Using the black spudger, carefully remove the cord connecting the battery to the motherboard.

Carefully remove the cable connecting the nfc chip to the motherboard.

Attach the Philips #1 bit to the driver adapter. With the driver adapter, release the one 7.0 mm screw that is attaching the motherboard to the casing. Lift the motherboard out of the case and the battery is revealed.

Remove the cord that connects the ports board to the motherboard. Put the motherboard to the side.

Using the black spudger, loosen the brace holding in the battery. To remove the brace, turn it 90 degrees clockwise and lift it up from its socket.

LENOVO IDEAPAD S500 - S500 TOUCH – AC ADAPTER TESTING – HOW TO CHECK THE BATTERY PACK – HOW TO REMOVE THE BATTERY

Lenovo IdeaPad S500 - S500 Touch – AC adapter testing – How to check the battery pack – How to remove the battery

Lenovo IdeaPad S500 - S500 Touch

Restore of factory default
The Lenovo computers come with pre-installed OneKey Recovery System.In order to save application files and the initial backed up files of the system, the hard disk in a Lenovo computer includes a hidden partition when it is shipped. If you need to restore the system to the point of your first boot up, just enter Lenovo OneKey Recovery System and run System Recovery.

To verify a symptom, follow the steps below:
1. Turn off the computer.
2. Remove the battery pack.
3. Connect the AC adapter.
4. Make sure that power is supplied when you turn on the computer.
5. Turn off the computer.
6. Disconnect the AC adapter and install the charged battery pack.
7. Make sure that the battery pack supplies power when you turn on the computer.
If you suspect a power problem, see the appropriate one of the following power supply checkouts:
“Checking the AC adapter”
“Checking operational charging”
“Checking the battery pack”
Checking the AC adapter
You are here because the computer fails only when the AC adapter is used.
If the power-on indicator does not turn on, check the power cord of the AC adapter for correct continuity and installation.
To check the AC adapter, follow the steps below:
1. Unplug the AC adapter cable from the computer.
2. Measure the output voltage at the plug of the AC adapter cable. See the following figure:

Note: Output voltage for the AC adapter pin No. 2 may differ from the one you are servicing.

3. If the voltage is not correct, replace the AC adapter.
4. If the voltage is acceptable, do the following:
Replace the system board.
Note: Noise from the AC adapter does not always indicate a defect.
Checking operational charging
To check whether the battery charges properly during operation, use a discharged battery pack or a battery pack that has less than 50% of the total power remaining when installed in the computer.

Perform operational charging. If the battery status indicator or icon does not light on, remove the battery pack and let it return to room temperature. Reinstall the battery pack. If the charge indicator or icon is still off, replace the battery pack.
If the charge indicator still does not light on, replace the system board. Then reinstall the battery pack. If it is still not charged, go to the next section.
Checking the battery pack
Battery charging does not start until the Power Meter shows that less than 95% of the total power remains; under this condition the battery pack can charge to 100% of its capacity. This protects the battery pack from being overcharged or from having a shortened life.
To check your battery, move your cursor to the Power Meter icon in the icon tray of the Windows taskbar and wait for a moment (but do not click it), and the percentage of battery power remaining is displayed. To get detailed information about the battery, double-click the Power Meter icon.
Note: If the battery pack becomes hot, it may not be able to be charged.
Remove it from the computer and leave it at room temperature for a while. After it cools down, reinstall and recharge it.

How to remove Battery pack

Unlock the manual latch 1. Slide the spring-loaded latch to the unlocked position 2 to eject the battery pack. Lift up the inner edge of the battery pack, pivoting it on the outer edge 3. Gently raise the battery pack in the indicated direction 4 to remove it.

How to remove Base cover

Remove the screws 1. Then remove the base cover 2.