REPAIRING AND NOT THROWING AWAY

REPAIRING AND NOT THROWING AWAY

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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..............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!

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All posts are presented here for informative, historical and educative purposes as applicable within fair use. NOTHING HERE IS FOR SALE !

Tuesday, 18 February 2020

REPAIR / SERVICING TV LG 32LH570U

Technical description and composition of the LG 32LH570U TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 32LH570U
Chassis / Version: LD66K / LD66Y
Panel: HC320DXN-VHVS1-214X
LED backlight: 32LH51_HD SSC_32lnch_HD_REV05_150925
T-CON: CPWBX5409TP 04, K5387TP
LED driver (backlight): integrated into MainBoard
PWM LED driver: MP3378E
Power Supply (PSU): DA-48G19 Adapter 19V 2.53A
MainBoard: EAX66853404 (1.1) RS6DL21EHT 4.01.26
IC MainBoard: EEPROM: 24C256
Tuner: TDJM-G301D EBL61741401
Control: AKB74915325, IR: EBR80772102 LF5100; Wi-Fi: EAT61813903 TWFM-B006D BEJTWFMB006D
Specifications 32LH570U
LG 32LH570U
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 32CS560 TV does not turn on and does not show any signs of turning on. There are no reactions to the control buttons or the remote control.
With such manifestations, in most cases, the DA-48G19 power module turns out to be faulty.
This TV model is equipped with an external power supply unit such as DA-48G19 Adapter 19V 2.53A, which the owner can purchase independently, and repairing it may not always be advisable, however, sometimes it makes sense to open it and eliminate simple typical defects typical for IIP. It is necessary to measure the output voltages in the secondary circuits, and if they are absent, check the operability of the power switches of the converters and rectifier diodes for a possible breakdown (short circuit).
In the event of breakdowns in the secondary circuits, the converter may emergencyly operate in the short circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch may be PWM (PWM). It is checked only by replacement with a known good one.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
In most of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It should be remembered that it is not possible to determine the open circuit in the LED lines without disassembling the panels with a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then it is necessary to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow you to open the LED in the forward direction or dual LEd are used, then the PN junction of the emergency zener diode can indirectly serve as a health indicator. In case of LED-a failure, the zener diode PN junction will either be cut off or broken into short-circuit.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the EAX66853404 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software).
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the tuner TDJM-G301D EBL61741401. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.
To reduce the backlight current in LED drivers with the MP3378E PWM controller, it is necessary to proportionally increase the total resistance of the resistors from pin 3 (RISET) to the chassis. Calculation of current in milliamperes and resistance in kilo-ohms 977 / Rset for each channel. Parallel channels are summed. For example, for four parallel channels and a RISET 10 KOhm resistance, the total current will be 97.7 * 4 = 391 mA.

More details on this page

The appearance of the MainBoard EAX66853404 is shown in the figure below:
EAX66853404
EAX66853404 can be used in TVs:
LG 32LH595U (Panel HC320DXN-ABVS2-5112), LG 32LH570U (Panel HC320DXN-VHVS1-214X).
The appearance of the power supply
Main features of the device LG 32LH570U:
Installed matrix (LED-panel) HC320DXN-VHVS1-214X.
The matrix control uses the Timing Controller (T-CON) CPWBX5409TP.
To power the backlight LEDs, a converter is used, combined with the main board EAX66853404, controlled by the MP3378E PWM controller.
To power all the internal components of the LG 32LH570U TV, an external source such as DA-48G19 Adapter 19V 2.53A is used.
MainBoard - the main board (motherboard) is an EAX66853404 module, using EEPROM chips: 24C256 and others.
The TDJM-G301D EBL61741401 tuner provides TV reception and channel tuning.

Posted By: FRANK at 08:28
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