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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Tuesday, 3 March 2020

REPAIR / SERVICING TV LG 47LM620T

Technical description and composition of the LG 47LM620T TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 47LM620T
Chassis / Version: LD22
Panel: LC470EUE (SE) (F3)
LED backlight: 6922L-0017A LEFT, 6922L-0018A RIGHT; 47
T-CON: 6870C-0401B - 32/37/42/47/55 FHD TM120 Ver 0.2
LED driver (backlight): integrated into PSU; 58.5V 1.26A
PWM LED driver: 2843B, GPCD2430A, 100BCA148AZOH
MOSFET LED driver: 86106LZ
Power Supply (PSU): EAX64310401 (1.4) - PLFD-L101A - LGP4247H-12LPB EAY62512701
PWM Power: L6599AD (PWM resonant), HS01G (PFC), STR-A6059H (Standby)
MOSFET Power: 18NM60N, 13NM60N
MainBoard: EAX64307906 (1.0)
IC MainBoard: CPU: LGE2112 1215-BTAH, NAND: KLM2G1HE3F-B001, Sound: STA380BWE, EEPROM: AT24C256C
Tuner: TDSN-G351D
Specifications 47LM620T
LG 47LM620T
General repair guidelines for TV LCD LED
In the case when the 47LM620T does not turn on, does not respond to the remote control and buttons on the front panel, does not blink bulbs and does not show any signs of operability, the EAX64310401 power supply module (1.4) is probably faulty in this case. In the general case, first of all, it is necessary to check the electrolytic capacitors of the secondary rectifier filters and the fuse at the input of the network. If it is cut off, then it is necessary to check the rectifier bridge diodes and the key transistor of the converter for a breakdown of the PN junctions, which can either be on a separate radiator or integrated with a PWM controller in a common chip. Options are 18NM60N, 13NM60.
The reasons for the breakdown of the power switch in switching power supplies (IIPS) can be different, for example, a malfunction of semiconductor cells or electrolytic capacitors in the stabilization circuits of the primary circuit, as well as a failure in the operation of the PWM resonant (PWM resonant) PWM controller chip, FAN7930 (PFC), STR-A6059H (Standby) or breakage of resistors in its harness.
If the LG 47LM620T TV does not have an image, but there is sound, a malfunction in the backlight circuits of the LC470EUE (SE) LED panel (F3) is likely.
To check the health of the LEDs, as well as contact connections in the ruler circuit, the panel must be disassembled.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, black to the cathode). In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as a health indicator. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
The EAX64307906 motherboard must be checked if there is no reaction to the remote control and function buttons, the standby indicator blinks or lights up continuously. In such cases, if the converters or power regulators of the microcircuit are working, a software update may be necessary.
In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its CPU chips: LGE2112 1215-BTAH, NAND: KLM2G1HE3F-B001, Sound: STA380BWE and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
If you suspect a malfunction of the TDSN-G351D tuner, first of all, you need to verify the correctness of the software, as well as the presence of the necessary levels of supply voltage and pulses of data exchange with the processor via the I2C bus at the corresponding terminals of the tuner.
Attention to the owners! Attempts to repair the LG 47LM620T TV independently are not recommended by the manufacturer and can lead to serious negative consequences!
Service manual / schematic diagram ----------------> LG 47LM620S, 47LM620T, 47LM625S CHASSIS: LD22E.

schematic diagram ----------------> EAX64310401 LGP4247H-12LPB EAY62512701 Power supply


 The appearance of the MainBoard EAX64307906 is shown in the figure below:
EAX64307906
EAX64307906 can be used in TVs:
LG 32LM640T ZA (Panel LC320EUA PE F2), LG 32LS570T (Panel LC320EUN (SE)(M2)), LG 47LM620S (Panel LC470EUE (SE)(F4)), LG 42LM670T (Panel LC420EUG(PE)(F2)), LG 42LM640T 42LM640S (Panel LC420EUG (PE)(F1)), LG 42LM620T (Panel LC420EUE (SE)(F1)), LG 47LM660T (Panel LC470EUG (PE)(F1)), LG 42LS570T (Panel T420HVN01.0), LG 42LS570S ZB (Panel LC420EUE (SE)(M1)), LG 42LM669T (Panel LC420EUG (PE)(F2)), LG 42LM669S (Panel LC420EUG (PE)(F1)), LG 37LM620T (Panel LC370EUN (SE)(F2)), LG 47LM669 (Panel LC470EUG (PE)(F2)), LG 32LS570S ZB (Panel LC320EUN (SE)(M2)), LG 47LM620T (Panel LC470EUE (SE)(F3)), LG 47LM761T ZA (Panel LC470EUH (PE)(F1), LG 32LM620S (Panel LC320EUN (SE)(F2) ), LG 47LM670T 47LM670T-ZA.BRUWLJU (Panel LC470EUG (PE)(F1)), LG 42LM660S 42LM660S-ZA.BRUWLJU (Panel LC420EUG (PE)(F1)), LG 42LM660T 42LM660T-ZA.BRUWLJU (Panel LC420EUG (PE)(F1) ), LG 32LM620T (Panel LC320EUN (SE)(F3)), LG 55LM620T 55LM620T-ZE (Panel LC550EUE (SE)(F1)).
PSU Advanced
The 47LM620T model uses the EAX64310401 power supply unit using the PFC (Power Factor Correction) node - an active filter of the highest harmonics of the current consumption. In fact, it is a step-up converter based on the HS01G PWM controller, which eliminates the charge current of the electrolytic capacitor of the rectifier filter directly from the network through open diodes when its charging current is determined by its reactance.
As a result of the operation of the converter, the envelope of the high-frequency pulses of the input current of the converter will repeat the shape and phase of the input voltage. The health of the PFC node can be indirectly judged by the presence of an increased constant voltage (about + 380V) on the capacitor of the rectifier network in operating mode.
The appearance of the power supply
Main features of the device LG 47LM620T:
Installed matrix (LED-panel) LC470EUE (SE) (F3).
The matrix control uses the Timing Controller (T-CON) 6870C-0401B.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by a PWM controller 2843B, GPCD2430A, 100BCA148AZOH. As power elements of the LED driver, keys of type 86106LZ are used.
The necessary supply voltages for all nodes of the LG 47LM620T TV are generated by the EAX64310401 power supply module or its analogs using L6599AD (PWM resonant), HS01G (PFC), STR-A6059H (Standby) microcircuits and power switches of the 18NM60N, 13NM60N type.
MainBoard - the main board (motherboard) is an EAX64307906 module using CPU chips: LGE2112 1215-BTAH, NAND: KLM2G1HE3F-B001, Sound: STA380BWE, EEPROM: AT24C256C and others.
The TDSN-G351D tuner provides television reception and channel tuning.
Posted By: FRANK at 01:46
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