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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Friday 28 February 2020

REPAIR / SERVICING TV LG 42LS570T

Technical description and composition of the LG 42LS570T TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 42LS570T
Chassis / Version: LD22 * / LC22
Panel: T420HVN01.0
LED backlight: LG Innotek 42İnch 7030PKG 60EA
T-CON: 42T23-C00 T420HVN01.0 CTRL BD
LED driver (backlight): BD T320HVN01.1 32T20-D03
Power Supply (PSU): EAX64427001 (1.4) EAY62608801, PSLF-L116A, 3PAGC10083A-R, LGP42L-12P
PWM Power: FAN7930BMX (PFC), ICE3BR4765JZ (Standby DIP-7), L6599AD
MOSFET Power: STD10NM60N, STD7NM60N
MainBoard: EAX64307906 (1.0) EBR75226810
IC MainBoard: CPU: LGE2112 1215-BTAH, NAND: KLM2G1HE3F-B001, Sound: STA380BWE
Tuner: TDSN-G351D
Control: AKB73615306, IR: EBR74986702 LM35-55
Specifications 42LS570T
LG 42LS570T
General repair guidelines for TV LCD LED
Possible manifestations of defects
- LG 42LS570T TV does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
Failure in such cases should begin to be sought in the power supply circuits of the EAX64427001. It is necessary to measure its output voltages, and in case of their absence (full or partial), it is necessary to check the serviceability of power switches (STD10NM60N, STD7NM60N) of converters and rectifier diodes for possible short circuit.
In case of breakdowns of semiconductors in secondary circuits, the converter can usually operate abnormally in short circuit mode, and during short circuit in the power elements of the primary circuit, the main fuse often 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 chips FAN7930BMX (PFC), ICE3BR4765JZ (Standby DIP-7), L6599AD are usually checked by replacing with new, 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.
A malfunction is usually most likely in these cases at the backlight nodes of the display matrix. 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.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as a health indicator. In faulty LEDs, the zener diode 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 EAX64307906 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). When repairing an MB board, you need to check its CPU components: LGE2112 1215-BTAH, NAND: KLM2G1HE3F-B001, Sound: STA380BWE. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
The malfunction of the TDSN-G351D tuner is established after checking the software and all the supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
TV users and owners need to remember that attempts to self-repair a LG 42LS570T TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
 SCHEMATIC DIAGRAM ---------->  LG CHASSIS: LD22E, MODEL: 42LS570S, 42LS570T, 42LS575S, 42LS575T - ZB/ZD.

PSU  SCHEMATIC DIAGRAM ---------->  LGP42L-12P EAX64427001 EAY62608801


 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)).
The appearance of the power supply
Main features of the device LG 42LS570T:
Installed matrix (LED-panel) T420HVN01.0.
The matrix control uses the Timing Controller (T-CON) 42T23-C00.
To power the backlight LEDs, the BD LED driver is used.
The necessary supply voltages for all nodes of the LG 42LS570T TV are generated by the EAX64427001 power supply module or its analogs using FAN7930BMX (PFC), ICE3BR4765JZ (Standby DIP-7), L6599AD microchips and power switches of the STD10NM60N, STD7NM60N type.
MainBoard - the main board (motherboard) is an EAX64307906 module using CPU chips: LGE2112 1215-BTAH, NAND: KLM2G1HE3F-B001, Sound: STA380BWE and others.
The TDSN-G351D tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T420HVN01.0
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: AMVA, Normally Black, Transmissive
Active Area: 930.24x523.26 mm
Surface: Antiglare (Haze 2%), Hard coating (3H)
Brightness: 350 cd / m²
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
Posted By: FRANK at 07:22
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