Master Electronics Repair !

Welcome to Master Electronics Repair! website.Here you will find:Service Modes, Circuit Diagrams,Service manuals, Firmware Update procedure, Disassemble procedure, Universal remote control setup codes, Troubleshooting, Diagnosing, Measuring, and more.... of many of LCD/LED TV/Displays,others various electronic apparates,trough many technical notes and tips/tricks to help repairing/fixing Troubles/ faults,for electrical technicians.This site helps you to save the Earth from electronic waste!

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!

Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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Note that if you don't find what you searched for, try it after a period of time; the site is a never ending job !

..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

©2010, 2011, 2012, 2013, 2014 Frank Sharp - You do not have permission to copy photos and words from this blog, and any content may be never used it for auctions or commercial purposes, however feel free to post anything you see here with a courtesy link back, btw a link to the original post here , is mandatory.
All posts are presented here for informative, historical and educative purposes as applicable within fair use. NOTHING HERE IS FOR SALE !

Friday, 29 March 2019

LG LAB5901RN CAR CD/MP3/WMA RECEIVER – FIRMWARE UPGRADE – SCHEMATIC

How to upgrade the firmware _ Circuit Diagram _ LG-LAB5901RN - Car Audio System_How to connect the Power Supply

GENERAL
Output Power 53 W x 4 CH (Max.)
Power Source DC 12 V
Speaker impedance 4 Ω
Ground System Negative
Dimensions (W x H x D) 188 x 100 x 186 mm
Net Weight 1.59 kg.

TUNER: FM
Frequency Range 87.5 to 107.9 or 87.5 to 108 MHz
S/N Ratio 55 dB
Distortion 0.7 %
Usable Sensitivity 12 dBµV
AM (MW)
Frequency Range 520 to 1720 or 522 to 1620 kHz
S/N Ratio 50 dB
Distortion 1.0 %
Usable Sensitivity 28 dBµV

HOW TO CONNECT AUDIO SET TO POWER SUPPLY

It is sufficient only to supply power for upgrade.
• Shown from the right figure, connect yellow line (Battery) and red line (Ignition) to plus and minus terminal respectively.
• Jack is connected to the audio set via its shapes matched each other.
• We need power supply for operation of audio set (Voltage : 12~15 V Current : Over 2 A)
Before connection between set and power supply, adjust voltage level to 15 V typically (It is okay up to 12 V.) Power Supply has a variety of shapes and capacity of voltage and current. At first check these things.

FIRMWARE UPGRADE METHOD [MAIN/CD FIRMWARE UPGRADE]

Confirmation of version information
> Change the Source of audio set to tuner. (Default: tuner)
> Turn power off using power key.
> Press power key for 5 sec. (After power on, continue pressing)
> After 5 sec, beep sound rings two times. Then version information would show up at display.
> In order to check version of MAIN/CD system, Press band key.
> With beep Sound version of system for main, CD is displayed in sequence.

Upgrade Program reading
Insert update CD in ACC on state and then [READING-> FILE CHK-> DOWNLORD?] is displayed in order

Upgrade start
In order to start upgrade, Press SCAN key (No2.) long (more then 2 sec) until “CHECK CD” Display on the LCD.

Upgrade progress display
Upgrade is in progress now. [ CHECK CD > ERASE > WRITE > I-VRF > D-VRF ]

Upgrade Completion
When Upgrade finished, the display shows up “DOWN OK”. After a while, the audio set is reset automatically.

Caution: If power is off on the way of upgrading firmware, the set can’t be recovered. Therefore pay lots of attention for power not to be off.

USB FIRMWARE UPGRADE

Confirmation of version information
> Change the source of audio set to tuner. (Default : tuner)
> Turn power off using power key.
> Press power key for 5 secs. (After power is on, continue pressing)
> After 5 secs, beep sound rings two times. Then the version information would show up at display.
In order to check version of USB system, press band key. With beep sound, version of systems for main, CD and USB is displayed in sequence.

Upgrade Preparation
At first check that audio set is in tuner mode. With power key, turn it off. Make it sure to insert USB device which has upgrade file.

Upgrade start
Press SRC key for 5 secs. After power is on, continue pressing. And then the audio set is changed to USB upgrade mode.

Upgrade progress display
Upgrade is in progress now. It takes about 10 secs.

Upgrade completion
Upgrade finished, the right display shows up. After a while, the audio set is reset automatically.
Caution: If power is off on the way of upgrading firmware, the set can’t be recovered. Therefore pay lots of attention for power not to be off.

Thermal protection circuit
A built-in thermal protection circuit (TSD:Thermal shut down) prevents thermal damage to the IC. All outputs except VDD (pin14) and FREG (pin2&3) are switched off when the circuit operates; revert to the original state when the temperature drops to a certain level.

Overvoltage protection circuit
The overvoltage protection circuit (surge protector) turns off all outputs without Vdd, when VB voltage is more than about 21V. And the overvoltage protection circuit (surge protector) turns off Vdd output with other all outputs, when VB voltage is more than about 26V. When the overvoltage protection operates on VB>=18V condition, the stand by current increases.

Over current protection circuit
FREG_B (pin2), ILMOUT (pin4), CDOUT (pin6), DSPOUT (pin7), AUDIOOUT (pin10), EXITOUT (pin12), VDDOUT (pin14) output circuits are built-in over current protection circuit based on the respective output current. These over current protection circuits limit the current with a curve shape of “7” in the voltage-current graph. This prevents IC destruction due to over current.

Before exchange power amp IC(TB2946) for no audio problem, you have to check below list.
Check VCC (pin 20,6) & GND
Check input pin 11,12,14,15
Check Standby, pin 4 : Follow the below list.

Check Mute function, pin 22 : Follow the below list.

Check Ripple pin 10. : Normally it is high (about 10 V)

Re-soldering all the pin of IC. : Prevent crack of solder line.