ELENBERG TV 707 CIRCUIT DIAGRAM LC85F3264, LA76810, LA7542 AND PHILCO PH55E51 LED TV POWER SUPPLY (SMPS) SCHEMATIC DIAGRAM

Elenberg TV707 Schematic and PWB layout

Schematic diagram

Philco PH55E51 SMPS BOARD schematic diagram

 

PHILIPS PBS20BT PORTABLE SPEAKER BOX HOW TO DISASSEMBLE

How to disassemble Philips portable speaker box, Schematic diagram

Philco [Philips] speaker PBS20BT – Disassembly, Exploded view, Circuit diagram

Schematic

Exploded view

SAMSUNG MX F730 MINI SYSTEM POWER BOARD SCHEMATIC DIAGRAM / AOC LC42H133, POWER BOARD (SMPS) SCHEMATIC DIAGRAM / PHILCO PH32ME POWER BOARD SCHEMATIC DIAGRAM

 

Samsung MX F730 Mini System  Power board schematic

Used IC: NCP1379, SPA17N80 (FET)

AOC Power Board; 715G3829P03W30003S schematic diagram

Used ICs: FAN7529MX, A6069H, LD7523GS, OZ9976GN-C-0-TR

CCE39G, Philco PH32ME CCE D32 – Power board schematic

Used ICs: L6562, LD7535 or SG6848, F13N50 (FET), PC817B (Opto-coupler)

PHILCO PH28B25DG LED TV - SCHEMATIC

Philco PH28B25DG LED TV - Schematic

Using Ics: MP1582, MP1495, MP2143,  NC/AZ1117, RD29581G, TC58NVG0S3ETA00, M24C32MN/NC, RT910NBGCP, 7N65(SMPS FET), TEA1733(SMPS CONTROL), MC34063, MP3394

PHILCO PS2914 CRT TV HOW TO ENTER THE SERVICE MODE, ADJUSTMENT DETAILS, FULL SCHEMATIC LA5-A CHASSIS USING LA76818AM (CHROMA, IF, VIDEO JUNGLE), QXXAVC479P (CPU)

The primary source of X-RADIATION in television receiver is the picture tube. The picture tube is specially constructed to limit X-RADIATION emissions. For continued X-RADIATION protection, the replacement tube must be the same type as the original including suffix letter. Excessive high voltage may produce potentially hazardous X - RADIATION. To avoid such hazards, the high voltage must be maintained within specified limit. Refer to this service manual, high voltage adjustment for specific high voltage limit. If high voltage exceeds specified limits, take necessary corrective action. Carefully follow the instructions for + B1 volt power supply adjustment, and high voltage check to maintain the high voltage within the specified limits.

IC802 (EEPROM) Replacement
When IC802 (EEPROM) is replaced, IC801 (CPU) will automatically write the initial reference data into IC802 for basic TV operation.  However, the bus data should be checked and some bus data should be set up before attempting the service adjustments.

Initial Bus Data Setup
Note: When IC802 (EEPROM) is replaced, following Service Menu should be set up for proper TV operation before attempting the service adjustments.

NO.01 RFAGC (Adjust the data 06 to10)
NO.05 V-SCO (Adjust the data 17 to 11)
NO.06 V-LIN (Adjust the data 15 to 16)
NO.11 VLI60 (Adjust the data +1 to 0)
NO.19 RDRIV (Adjust the data 63 to 64)

NO.82 CHMT (Adjust the data 12 to 05)

NO.308 R08 (Adjust the data FF to 21)

NO.84 RELAY (Adjust the data 80 to 20) NO.309 R09 (Adjust the data FF to 95)

NO.85 CCD (Adjust the data 26 to 31)
NO.300 R00 (Adjust the data FF to 93)
NO.301 R01 (Adjust the data FF to 0E)

NO.310 R10 (Adjust the data FF to 50)
NO.311 R11 (Adjust the data FF to 00)

↓

NO.20 GDRIV (Adjust the data 07 to 08) NO.302 R02 (Adjust the data FF to 00)

NO.371 R71 (Adjust the data FF to 00)
NO.372 R72 (Adjust the data FF to A2)

NO.21 BDRIV (Adjust the data 63 to 64)
NO.24 B-YD (Adjust the data 10 to 08)
NO.25 R-YD (Adjust the data 10 to 08)

NO.303 R03 (Adjust the data FF to 00)
NO.304 R04 (Adjust the data FF to 01)
NO.305 R05 (Adjust the data FF to 00)

NO.68 AFCAV (Adjust the data 00 to 01) NO.306 R06 (Adjust the data FF to 00)

NO.81 POMT (Adjust the data 12 to 08)

NO.307 R07 (Adjust the data FF to 00)

Enter the Service Menu

While pressing the MENU button on the television, press the Number Key 2 on the remote control unit.  The Service Menu now appear.

Service Adjustments:
Press the CHANNEL UP or CHANNEL DOWN button on the remote control handset to select the desired service menu item you want to adjust.
Use the VOLUME + or - to adjust the data. The + or - button will increase or decrease the data sequentially.

Exit from the Service Menu
Press the MENU button to turn off the Service Menu display.
The data which is set in the service mode is stored into the memory IC automatically.

Service Adjustments:  On-screen Service Menu

Following table shows the initial values which have been stored in the CPU ROM, and items for the service adjustments.
When IC802 (EEPROM) is replaced, check the bus data to confirm they are the same as below. The shaded menu should be checked and be set up or readjusted according to the procedures described in the following pages.
Initial Setup Data marked with an * should be changed from Initial Value Data.

[RFAGC] AGC

NOTE: Do not attempt this adjustment with weak signal.
1. Tune the receiver to most clearest (or strongest) VHF station in your area. Set the brightness and contrast controls to maximum. Set the colour control to minimum.
2. Select Item No. 01 [RFAGC] in the service mode.
3. Change value until the snow noise just disappears.
4. Exit from the service mode.

[H-PHA] HORIZONTAL CENTRE

1. Recceive a monochrome circular pattern.
2. Set the brightness and contrast to normal.
3. Select Item No. 02 [H-PHA] in the service mode.
4. Change value to be optimum horizontal centre position.
5. Exit from the service mode.

[V-POS] VERTICAL CENTRE

1. Receive a monochrome circular pattern.
2. Set the brightness and contrast to maximum.
3. Select Item No. 03 [V-POS] in the service mode.
4. Change value to be optimum vertical centre position.
5. Exit from the service mode.

[V-SIZ] VERTICAL SIZE

Receive a monochrome circular pattern.
2. Set the brightness and contrast to maximum.
3. Select Item No. 04 [V-SIZ] in the service mode.
4. Change value to be optimum vertical size.
5. Exit from the service mode.

[OSDHP] OSD POSITION

1. Receive a monochrome circular pattern.
2. Set the brightness and contrast to normal.
3. Select Item No. 12 [OSDHP] in the service mode.
4. Change value to be proper OSD position.
5. Exit from the service mode.

[CCD] CAPTION H-POSITION ADJ

Tune receiver to a caption channel.
2. Check that CAPTION position is in the horizontal
center of the screen. If CAPTION center is too right or left, perform steps 3-6. (See figure below.)
3. Select Item No. 85 [CCD] in the service mode.
4. Adjust data with + or - key for proper horizontal center.
5. Exit from the service mode.

Items 16-23 GREY SCALE

1. Receive a monochrome circular pattern.
2. Set the brightness and colour to normal, contrast to maximum.
3. Enter to the service mode.
4. Set each value of Item-16 RBIAS, 17 GBIAS, 18 BBIAS mode to 00. Set each value of Item-19 RDRIV, 21 BDRIV mode to 63, 20 GDRIV to 08.
5. Select Item-22 mode to be one horizontal scanning line and turn the screen volume on the FBT to obtain just visible one coloured line.
6. Press the 1 (Red Bias +), 4 (Red Bias -), 2 (Green Bias +), 5 (Green Bias -), 3 (Blue Bias +) or 6 (Blue Bias -) button to adjust the brightness of each colour until a dim white line produced. Please see the control button allocations in this mode.
7. Select Item-23 DRV mode to enter the white balance adjusting mode.
8. Press the 7 (Red Drive +), RECALL (Red Drive -), 8 (Blue Drive +) or 0 (Blue Drive -) button alternately to produce normal black and white picture.
9. Exit from the service mode.
10. Check for proper grey scale tracking at all brightness levels.
NOTE: If the grey scale adjustment is made after picture tube replacement, check the high voltage.

Adjustment-2 (MTS Adjustment)

Enter the Service Menu
While pressing the MENU button on the television, press the Number Key 3 on the remote control unit. The Service Menu now appear.

Service Adjustments:
Press the CHANNEL UP or CHANNEL DOWN button on the remote control handset to select the desired service menu item you want to adjust.
Use the VOLUME + or - to adjust the data. The + or - button will increase or decrease the data sequentially.

Exit from the Service Menu
Press the MENU button to turn off the Service Menu display.
The data which is set in the service mode is stored into the memory IC automatically.

SOUND LEVEL ADJUSTMENT

1. Connect a signal to the antenna terminal with audio signal of 1KHz at 100% modulated.
2. Connect a DC Volt-Meter to TP-317 ( pin-38 of IC3401) and the ground.
3. Switch the TV set on, and set the Surround OFF.
Press and hold the MENU button on the TV set, and press “3” button on the remote control transmitter to enter to the service mode.

5. Adjust voltage to become DC 400mVrms±20mVrms at TP317 by pressing the VOLUME(+/-) button on the remote control or TV set.
6. To exit from the service mode, press the MENU button.

STEREO SEPARATION ADJUSTMENT

1. Connect an oscilloscope:
Probe-A to TP-317 (pin-38 of IC3401) and the ground.
Probe-B to TP-318 (pin-39 of IC3401) and the ground.
2. Turn on the TV set, and receive the multi sound programme.
3. Press and hold the MENU button on the TV set, and press “3” button on the remote control transmitter to enter the service mode.
4. Select “LOW SEPARATION” by pressing the CHANNEL UP/DOWN button on the remote control or TV set.

5. Adjust the level of 300Hz at TP-317 (pin-38 of IC3401) to become minimum level by pressing the VOLUME(+/ -) button on the remote control or TV set.

6. Select “HI SEPARATION” by pressing the CHANNEL UP/DOWN button on the remote control or TV set.

7. Adjust the level of 4KHz at TP-318 (pin-39 of IC3401) to become minimum level by pressing the VOLUME (+/-) button on the remote control or TV set.
8. To exit from the service mode, press the MENU button.

Service Adjustment-3: FINE TUNING

This adjustment is used to do a fine tuning of the channels with poor reception after they have been stored by the automatic tuning.
This function is available for one channel only and the fine-tuned channel is memorised into IC802 (EEPROM). FINE TUNING
1. Enter the Service Menu
While pressing the MENU button on the television, press the “4” or MENU button on the remote control unit. The Service Menu now appear.

Service Adjustments:
Press and hold the VOLUME + or VOLUME – button on the remote control handset or TV set to make fine tuning adjustment. Press and hold the VOLUME + button for higher frequency tuning, and press and hold the VOLUME - for lower frequency tuning.

Fine tuning data value will be automatically stored in memory.

To return to normal TV mode, press the MENU button on the TV set or remote control handset. (Or will automatically return to normal TV mode after 5 seconds.)

FOCUS ADJUSTMENT

1. Receive the monochrome circular pattern.
2. Set the brightness to normal and contrast to maximum.
3. Adjust the focus control on the F.B.T. for the best focus on the screen centre.

+B POWER SUPPLY ADJUSTMENT

Connect a DC voltmetre to TP-”+B +130V” and the ground. Set the +B adjustment control (VR651) to middle range.
2. Set the brightness to normal and contrast to maximum.
3. Tune the receiver to an active channel and synchronized picture.
4. Adjust +B voltage to 130± 0.5 volt DC by using VR651.

HORIZ. WIDTH ADJUSTMENT

1. Receive a monochrome circular pattern.
2. Set the brightness and contrast to maximum.
3. If the picture is too wide, or narrow, adjust horizontal width control (VR462) for optimum width.
4. Select several other channels and check horizontal width.

HIGH VOLTAGE CHECK

Note: +B (+130V) Voltage and Grayscale Adjustment must be completed before attempting High Voltage Check.
1. Connect high voltage voltmeter negative lead to ground, and connect + lead to anode of picture tube.
2. Tune receiver to an active channel and confirm TV is operating properly.
3. The high voltage must be 28.5KV ± 1KV and less than 32KV at 0 beam current (Brightness and contrast minimum setting).
Note: If the picture tube is replaced, check the high voltage. The horiz. width adjustment affects the high voltage. Therefore, re-check the high voltage.

Protection Circuit

This TV set has a built-in power supply protection circuit.
It is provided to protect the TV set in case of a power supply circuit malfunctions. When something abnormality occurs during TV reception, the TV set goes to the standby mode.

When an abnormality occurs during TV reception, it causes pin 27 of the CPU to go continually Low voltage for about one second. The CPU detects that this has occurred and outputs the signal from pin 31 to switch off the power supply lines.

Releasing the protective circuit and restoring power supply

To release the protective circuit and restore power supply, turn the power to the TV set OFF and then ON again via either the main power switch or the ON-OFF button on the remote control. This will work only if the power supply trouble was temporary. If there is permanent trouble such as a damaged circuit, power cannot be restored and the circuit will have to be repaired.

Purity and Convergence Adjustment

CAUTION: The Convergence and Purity adjustments have been made at the factory. Readjustment should be made only after picture tube or deflection yoke replacement, following the steps below:

PURITY ADJUSTMENT
1. Demagnetise the picture tube and receiver using an external degaussing coil. When replacing picture tube or deflection yoke, mount deflection yoke and purity-convergence magnets assembly properly, see figures 1 and 4.
2. Turn Red and Blue guns off and provide only Green raster.  Rotate Screen control to fully counterclockwise. Rotate Red and Blue Bias controls fully counterclockwise. Slowly rotate Green Bias control clockwise to produce Green raster.
3. Loosen the screw holding the Deflection Yoke and remove the 3 Rubber Wedges, and slide the Deflection Yoke fully forward.
4. Rotate and spread the Tabs of the two Purity Magnets to centre the vertical green belt in the picture screen. The Purity Magnets are also adjusted to obtain vertical centring of the raster.
5. Slowly slide the Deflection Yoke backward until a uniform green screen is obtained.
6. Check the purity of the red and blue screens for uniformity, turn off other colours to check this (use bias controls).  Readjust the yoke position if necessary until all screens are pure.
7. Adjust each Bias control and screen control to obtain white raster. Refer to Gray Scale Adjustment. If part of the picture screen is coloured, adjust the Deflection Yoke position forward or backward slightly.

8. Tighten the mounting screw of the Deflection Yoke. Adjust Convergence next.
CENTRE CONVERGENCE ADJUSTMENT
1. Use a dot crosshatch pattern signal.
2. Turn Red and Blue guns on and turn off Green gun. Adjust the angle between the Tabs of the Four Pole Magnet 1 and 2, and superimpose the Red and Blue vertical lines in the centre area of the picture screen. Refer to figure.
3. Keeping the mutual angle of the Tabs of the Four Pole Magnet turn them together to superimpose the Blue and Red horizontal lines in the centre area of the picture screen. Refer to figure.
4. Turn Green gun on and adjust Six Pole Magnet 3 and 4 that the Green line superimposed on the Red/Blue lines.  This is the same procedure used in steps 2 and 3.
Refer to figure.
OUTER AREA CONVERGENCE ADJUSTMENT
Slightly loosen the screw holding the Deflection Yoke. Adjust the Deflection Yoke to converge the detail in the outer area (left side and right side) of the picture screen by orbital movement of the front of the Yoke, then secure the Deflection Yoke in appropriate position by putting the wedges as illustrated. Tighten screw holding the Deflection Yoke.

Schematic [Circuit diagram] full

LG FLATRON W1942S LCD MONITOR – AOC L32W831 – PHILCO 28T35DG LCD TVs – SMPS SCHEMATICS

AOC L32W831 – PHILCO [PHILIPS] PH28T35DG-LED TV – LG FLATRON W1942S LCD Monitor – SMPS & Back-Light inverter schematics

PHILCO [PHILIPS] -  SMPS SCHEMATIC – OB5296 (Power control) – NDF06n60ZG (Power Switching) _ PC817 (Photo-coupler) – MP3394 (Led Control)

AOC-L32W831 _  AN7529MX (Power Control) – W20NM60 (Power Switching) – 6599D (Backlight Incerter Control) – 2NM50 –Back-light inverter switching control).

LG FLATRON W1942S _ BACK-LIGHT INVERTER - FAN7314 (Back-light inverter control)

W1942S - LG FLATRON LCD MONITOR - SMPS SCHEMATIC _ SSS7N60B (Power Switching) – LAF0001 (Power Control) – LTV817M-V (Photo coupler)

CLICK ON THE PICTURES TO ZOOM IN

 

 

TV LED   IC  MP3394/MPS3394S LED Driver Diagnostics Throubleshooting

 

The earlier MP3394 was replaced by MPS3394S, which is an upgraded version of the same IC, and found in the 17IPS20 power supply board. It is the main heart of the backlighting LED drive and the failure of this IC can cause the TV not to start. This is a voltage step-up IC that takes 5-V to 28-V at its input pin 15 (Vin) and raises it to drive four independent strings of LEDs. It also performs other functions such as voltage regulation between the LED strings, and provides a dimming facility using pulse-width modulation (PWM). An important aspect of this IC is that it has built-in open and short LED protection circuitry. It is also able to sense the current and voltage of the LED matrix load and determine abnormal conditions. That means that if all the LEDs in the matrix go open or short, it will prevent the television from switching ON.
The IC has internal control logic that produces the GATE signal to drive an external MOSFET transistor. This is the transistor that is switched against an inductor to step-up the voltage, and the gate signal is produced only when the internal control logic detects normal conditions. It is able to determine normal/abnormal conditions through internal comparators, and one such is the LED Over-Voltage Protection (LED OVP) comparator that provides Short String Protection (SSP).

 

 

When the TV is switched ON, this IC is enabled through pin 2, by a voltage greater than 1.8-V. It first checks the circuit configuration, and then checks the over-voltage protection signal at (pin 12) to determine if the rectifier diode is open and whether the booster MOSFET (driven by the GATE signal) is short to ground. If the OVP voltage at pin 12 is lower than 70-mV (may be different for other board versions), then it disables itself and the TV will not start.
On the 17IPS20 board, the GATE signal is known as GATE_LED, which drives a bi-polar junction transistor (BJT) Q500 (BC858B). This transistor then drives Q502/Q503 MOSFET booster group of transistors to step-up the voltage (shown in the following pages of this article). In this circuit configuration the inductance coils are L500 and L501. The high voltage produced then goes into a group of rectifier diodes D503 and D504 producing a positive DC voltage for the LEDs. The over voltage protection signal is known as OVP_LED. Whilst all the LED strings take their power from this positive voltage source, they all have separate independent drain pins through the MPS3394S controller IC.
There are also other parameters to consider such as Under-Voltage Lock-Out (UVLO), which is determined by measuring the rising-edge of Vin. This parameter has to be between 3.5-V and 4.4-V, with 3.9-V being the typical value. It is a very clever IC as it can also detect open and short LED strings in the backlight array.

 

 Although this diagnostic cannot tell you the condition of each individual diode, it can indicate the condition of each string of diodes in the backlight matrix. The MPS3394S IC (SOIC16 package) drives four separate strings of LEDs through dedicated open drain output pins. LED string 1 is driven by pin 11, LED string 2 by pin 10, LED string 3 by pin 9, and LED string 4 by pin 8. It also monitors the voltages at these pins so that if there was a shorted LED in one of the strings then it would disconnect that string. If the voltage at any of these pins is greater than 6.1-V, then this condition triggers the short circuit protection mechanism for disconnecting the string at that pin. It is also possible to determine an open string, and in this case, this condition is detected when the pin voltage is lower than 196-mV.
Interestingly, this IC is designed such that it will always try to light at least one string if it is working. The only time when the step-up converter shuts-down completely is if all the strings were either open, or short. Therefore, before you rush off to eBay to buy a new chip, measure the voltages at these pins to make sure that the diodes are not faulty. Otherwise, you will end up wasting a lot of time and money!

 

PHILCO MINI SYSTEM – PH400N – SCHEMATIC

PHILIPS (PHILCO) MINI SYSTEM – PH400N – SCHEMATIC  (Circuit Diagram)

Used ICs: STR-X6757N – STR-W6753 – PTAS5630PHD (AMP OUTPUT IC)

SMPS SCHEMATIC

POWER AMPLIFIER SCHEMATIC

EXPLODED VIEW

CLICK ON THE PICTURES TO MAGNIFY

PHILCO TV PH24MR – LED TV – SMPS AND LED DRIVER INVERTER SCHEMATIC

PHILIPS (PHILCO) TV PH24MR – LED TV – SMPS and LED DRIVER INVERTER SCHEMATIC

Used ICs - LD7531A – 4N65 FET – BIT3251A – PH24MR LEDA2

SMPS & BACK-LIGHT INVERTER SCHEMATICS

CLICK ON THE SCHEMATICS TO ZOOM IN

PHILCO MINI SYSTEM PH200 - EXPLODED VIEW - CIRCUIT DIAGRAM

PHILCO MINI SYSTEM PH200 - EXPLODED VIEW - CIRCUIT DIAGRAM

Schematic & Exploded view_Philco Mini System PH200

Used ICs - TDA7265 (Power Amplifer)_7MD880 (Power Switching Control)

EXPLODED VIEW

POWER AMPLIFIER & MUTE CIRCUIT

SMPS SCHEMATIC