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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Sunday, 23 February 2020

REPAIR / SERVICING TV LG 37LN541U

Technical description and composition of the LG 37LN541U TV, type of panel and applicable modules. The composition of the modules.
LG LED
Model: 37LN541U
Chassis / Version: LD31B / LD36B
Panel: LC370DXE (SF) (R1)
LED backlight: 6916L-1137A, 6916L-1140A
T-CON: 6870C-0442B
LED driver (backlight): integrated into PSU
PWM LED driver: MAP3202
MOSFET LED driver: FDT86106
Power Supply (PSU): EAX64905301 (2.3) LGP42-13PL1
PWM Power: SSC1S311A (PWM flyback), NR891D
MOSFET Power: STP10NM60N
MainBoard: EAX64891306 (1.1) // EAX64891304
IC MainBoard: CPU: LGE2121-MC, DRAM: H5TQ2G63DFR, Flash: MX25L8006E, AUDIO: STA380BWF
Tuner: TDSQ-G601D (B)
Specifications 37LN541U
LG 37LN541U
General repair guidelines for TV LCD LED
Possible manifestations of defects
- LG 37LN541U does not turn on and does not show any signs of performance at all. Does not blink indicators and does not respond to control buttons.
In such cases, the EAX64905301 power supply is usually faulty. It is necessary to measure its output voltages, and if they are absent, check the operability of the power switches (STP10NM60N) of the converters and rectifier diodes for a short circuit probability.
In case of breakdowns in the secondary circuits, the converter, as a rule, can emergency work in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM circuits (PWM) SSC1S311A (PWM flyback), NR891D are usually checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
In such cases, the most likely malfunction of the LED backlight elements. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To check the LED strips, to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED transitions in forward bias, you can sometimes detect the presence of a PN junction of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the EAX64891306 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). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard - CPU: LGE2121-MC, DRAM: H5TQ2G63DFR, Flash: MX25L8006E, AUDIO: STA380BWF. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
The failure of the TDSQ-G601D (B) tuner is established after checking the software and all supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
Attention to users! Self-repair of the LG 37LN541U TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
schematic diagram ------------->  LG CHASSIS LD31B/LD36B MODEL 39LN54** 39LN54**-Z*.

schematic diagram PSU ----->  LG 37/39/42 Inch LGP3739-13PL1, LGP42-13PL1

 The appearance of the MainBoard EAX64891306 is shown in the figure below:
EAX64891306
EAX64891306 can be used in TVs:
LG 32LN540V (Panel LC320DUE (SF)(R1)), LG 42LN542V-ZD (Panel LC420DUE SFR3), LG 32LN541V (Panel LC320DUE (SF)(R1)), LG 42LA615V (Panel LC420DUE (SF)(U2) ), LG 32LA615V (Panel LC320DUE (SF)(U2)), LG 42LN540V (Panel LC420DUE (SF)(R1)), LG 42LN541V (Panel LC420DUE (SF)(R1)), LG 47LN540V (Panel LC470DUE (SF)(R1)), LG 32LB530U ZA (Panel LC320DXE (SG)(R1)), LG 39LN540V (Panel HC390DUN-VCFP1-11XX), LG 32LA643V (Panel LC320EUN (SF)(F1)), LG 32LN542V (Panel LC320DUE SF R1), LG 47LA615V (Panel LC470DUE (SF)(U2)), LG 47LA643V ZB (Panel LC470EUN (SF)(F2)), LG 32LN541U ZB (Panel HC320DXN-VHFP1 - 21XX / HC320DXN-VHFPA - 21XX), LG 32LN536U (Panel NC320DXN (SA)(P1)), LG 37LN541U (Panel LC370DXE (SF)(R1)).
The appearance of the power supply
Main features of the device LG 37LN541U:
Installed matrix (LED-panel) LC370DXE (SF) (R1).
The matrix control uses the Timing Controller (T-CON) 6870C-0442B.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the MAP3202 PWM controller. As the power elements of the LED driver, keys of the FDT86106 type are used.
The necessary supply voltages for all nodes of the LG 37LN541U TV are generated by the EAX64905301 power module or its analogs using SSC1S311A (PWM flyback), NR891D microchips and STP10NM60N type power switches.
MainBoard - the main board (motherboard) is an EAX64891306 module using CPU chips: LGE2121-MC, DRAM: H5TQ2G63DFR, Flash: MX25L8006E, AUDIO: STA380BWF and others.
The TDSQ-G601D (B) tuner allows you to receive television programs and tune to channels.
Posted By: FRANK at 08:35
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