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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Monday, 2 March 2020

REPAIR / SERVICING TV LG 47LA620V

Technical description and composition of the LG 47LA620V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 47LA620V ZA
Chassis / Version: LD33B
Panel: LC470DUE (SF) (U1)
LED backlight: 6637L-0024A, 6916L-1259A, 6916L-1260A, 6916L-1261A, 6916L-1262A
T-CON: 6870C-0444A, LC470DUE-SFR1
LED driver (backlight): integrated into PSU; 110V 0.4A
PWM LED driver: BD9483F
MOSFET LED driver: KF9N25, MDHT4N20Y
Power Supply (PSU): EAX64905501 (2.2) - LGP4750-13PL2
PWM Power: R2A20133D (PFC), 3BR4765JZ (Standby), SSC9527S (PWM Resonant)
MOSFET Power: 380N60E * 4
MainBoard: EAX64797003 (1.2) EBR76823128
IC MainBoard: CPU: LGE2122, H5TQ4G63AFR x2, H5TQ2G63AFR, NTP7513
Tuner: TSQ-G601D (B) EBL61240503
Control: AKB73756502; WIFI: TWFM-B006; IR: EBR76405801 LA6200
Specifications 47LA620V
LG 47LA620V
General repair guidelines for TV LCD LED
In the case when the 47LA620V does not turn on, does not respond to the remote control and buttons on the front panel, does not blink light bulbs and does not show any signs of operability, the EAX64905501 (2.2) power module, LGP4750-13PL2, is probably faulty in this case. In the absence of swollen filter capacitors of the secondary rectifiers, the diagnostics of the power supply should be started by checking the fuse and, if it is broken, it is first necessary to check all the power semiconductor elements of the primary circuit - diodes and transistors 380N60E * 4 for the possibility of an avalanche or thermal breakdown.
If the power keys of the pulse converter are not equal, you should pay attention to other elements in their bundling, which may be the result or cause of their breakdown.
If the LG 47LA620V does not have an image, there is sound and the channels are switched, there is a possibility of a malfunction in the backlight LED circuit of the Panel, or their power converter - LED driver. Sometimes, when turned on, the image appears and immediately disappears. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the backlight unit.
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.
When trying to repair the motherboard, you should first check the serviceability of linear stabilizers or power converters of microcircuits and, if necessary, update the software (software).
If it is not possible to replace the MB board (SSB), you need to check the health of its elements - CPU: LGE2122, H5TQ4G63AFR x2, H5TQ2G63AFR, NTP7513. Defective components should be replaced.
If there is no reception of television channels, but the TV is working properly from external devices, first of all you need to check the voltage of the tuner TSQ-G601D (B) EBL61240503 and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Attention! For users and owners of 47LA620V TVs who do not have the appropriate qualifications, knowledge and experience, we strongly recommend against self-repair attempts in order to avoid negative consequences that could lead to complete non-repairability of the device.
Service manual and schematic diagram -------------->   LG CHASSIS : LD33B MODEL : 47LA620S, 47LA620V, 47LA621V, 47LA6208.

 You can reduce the backlight current in TVs with LGP4750-13PL2 power supplies (EAX64905501) as follows. Current sensors in the R811-R818 LEDs - channel 1 and R829-R836 - channel 2. Resistors in the channels in pairs of 4.3 + 3.9 Ohm. You can reduce the backlight current by 25% by removing one pair of resistors in each channel.


 The appearance of the MainBoard EAX64797003 is shown in the figure below:
EAX64797003
EAX64797003 can be used in TVs:
LG 42LA620V (Panel LC420DUE (SF)(U1)), LG 32LN570V (Panel LC320DUE (SF)(R1)), LG 50LA644V (Panel LC500EUN (SF)(F1)), LG 47LA660V (Panel LC470EUG (PF)(F1)), LG 47LA621V (Panel LC470DUE (SF)(U1)), LG 42LA644V (Panel LC420EUN (SF)(F2)), LG 39LA620V ZA (Panel T390HVJ01.0), LG 42LA621V ZD (Panel LC420DUE (SF)(U1)), LG 32LA621V ZD (Panel LC320DUE (SF)(U1)), LG 32LN655V (Panel LC320EUB (PF)(M1)), LG 42LA667V (Panel LC420EUH (PF)(P1) ), LG 47LN613V (Panel LC470DUE (SF)(R4)), LG 32LA667V ZB (Panel LC320EUB (PF)(P1)), LG 55LA660V ZA (Panel LC550EUH (PF)(P1)), LG 47LA620V ZA (Panel LC470DUE (SF)(U1)), LG 32LN613V ZB (Panel LC320DUE (SF)(R4)), LG 42LN655V ZB.BRUZLJU (Panel LC420EUH (PF)(M1)), LG 32LA644V ZA (Panel LC320EUN (SF)(F1)), LG 42LN613V (Panel LC420DUE (SF)(R4)), LG 47LA690V ZB (Panel LC47EUH (PF)(P1)), LG 47LA662V (Panel LC470EUG (PF)(F1)), LG 42LA645V 42LA645V-ZC.BRUYLJU (Panel LC420EUN (SF)(F3)), LG 32LA660V (Panel LC320EUB (PF)(P1)), LG 47LA644V 47LA644V-ZA (Panel LC470EUN (SF)(F2)), LG 50LA667S (Panel T500HVD02.1), LG 47LA691V (Panel LC470EUH (PF)(P1)), LG 32LA662V (Panel LC320EUB (PF)(P1)).
The appearance of the power supply
Main features of the device LG 47LA620V:
Installed matrix (LED-panel) LC470DUE (SF) (U1).
The matrix control uses the Timing Controller (T-CON) 6870C-0444A.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the BD9483F PWM controller. As the power elements of the LED driver, keys of the type KF9N25, MDHT4N20Y are used.
The necessary supply voltages for all nodes of the LG 47LA620V TV are generated by the EAX64905501 power supply module or its analogs using the R2A20133D (PFC), 3BR4765JZ (Standby), SSC9527S (PWM Resonant) microcircuits and 380N60E * 4 power switches.
MainBoard - the main board (motherboard) is an EAX64797003 module using CPU chips: LGE2122, H5TQ4G63AFR x2, H5TQ2G63AFR, NTP7513 and others.
The tuner TSQ-G601D (B) EBL61240503 provides the reception of television programs and tuning to channels.

Posted By: FRANK at 02:06
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