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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Wednesday, 19 February 2020

REPAIR / SERVICING TV LG 32LN575S

Technical description and composition of the LG 32LN575S TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 32LN575S
Chassis / Version: LD33B
Panel: LC320DUE (SF) (R1)
LED backlight: 6916l-1437A (B2), 6916l-1438A (B1)
LED driver (backlight): integrated into PSU
PWM LED driver: MAP3202
MOSFET LED driver: 4NF20L, AP18N20GH
Power Supply (PSU): EAX64905001 EAY62810301 LGP32-13PL1
PWM Power: SSC1S311A (PWM flyback), NR891D (PWM Step-down 24/12)
MOSFET Power: MDF11N65B
MainBoard: EAX64797004 (1.1) EBT62345917
IC MainBoard: LGE2122 1402-BTAN, NAND: 3DAI8 JW857, H5TQ4G63AFR
Tuner: TDSQ-G501 (B) EBL6120403
Specifications 32LN575S
LG 32LN575S
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 32LN575S TV does not turn on and does not show any signs of operability at all. There is no reaction to either the remote control or the front panel control buttons.
In such cases, the EAX64905001 power supply is usually faulty. It is necessary to measure its secondary output voltages, and if they are absent, check the health of the power switches (MDF11N65B) of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during short circuit in the 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, power, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM chip SSC1S311A (PWM flyback), NR891D (PWM Step-down 24/12) can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
In most cases, the malfunction is caused by the lack of a backlight display. 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 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 an indicator of health. In the event of a LED malfunction, its 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 EAX64797004 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). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements LGE2122 1402-BTAN, NAND: 3DAI8 JW857, H5TQ4G63AFR. BGA chip malfunctions are usually easy to detect by warming up.
If the TV works normally from external devices, but does not tune into television channels, the tuner TDSQ-G501 (B) EBL6120403 may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Once again, remind users! Attempts to self-repair the LG 32LN575S TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
One of the typical failures of the LG 32LN575S often occurs in the LG panel LC320DUE (SF) (R1).
External manifestations: there is no image, the backlight does not work. In most of these cases, the LEDs turn out to be faulty, which, when tested, turn out to be either open or with broken internal zener diodes.
LEDs must be replaced, and the maximum current from the driver is limited to 10-20%.


To reduce the backlight current in televisions with the LGP32-13PL1 power supply unit (EAX64905001), you can increase the resistance of the current sensor, which consists of a set of pairs of low-resistance R822-R829 resistors, only 4 pairs of 3.9 + 4.3 Ohm.
Having repaired one pair, we increase the sensor rating by 25%, which proportionally reduces the current in the LEDs from 400 mA to 300 mA.


 More details on this page


Service manual and schematic diagram ----------------->  LG 32LN570R, 570U, 570V, 575S, 575U, 575V, 577S, 577V, 578V, 5707, 5758, 5778 Chassis LD33B.


Service manual PSU -------------------------------------------->  LG LGP32-13PL1, LGP32I-13PL1



The appearance of the MainBoard EAX64797004 is shown in the figure below:
EAX64797004
EAX64797004 can be used in TVs:
LG 42LA660S ZA 42LA660V (Panel LC420EUH (PF)(P1) 120 Hz), LG 32LA620V (Panel LC320DUE (SF)(U1)), LG 42LN570V (Panel LC420DUE (SF)(R3)), LG 50LA620V ZA (Panel LC500DUE (SF)(U1)), LG 32LN575S (Panel LC320DUE (SF)(R1)), LG 42LA669V 42LA669V-ZE.BRUZLJU (Panel LC420EUH (PF)(P1)).
The appearance of the power supply
Main features of the device LG 32LN575S:
Installed matrix (LED-panel) LC320DUE (SF) (R1).
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the MAP3202 PWM controller. As power elements of the LED driver, keys of the type 4NF20L, AP18N20GH are used.
The necessary supply voltages for all nodes of the LG 32LN575S TV are generated by the EAX64905001 power module or its analogs using SSC1S311A (PWM flyback), NR891D (PWM Step-down 24/12) microcircuits and MDF11N65B type power switches.
MainBoard - the main board (motherboard) is an EAX64797004 module using LGE2122 1402-BTAN chips, NAND: 3DAI8 JW857, H5TQ4G63AFR and others.
Tuner TDSQ-G501 (B) EBL6120403 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC320DUE-SFR1
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 698.4x392.85 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
Posted By: FRANK at 09:05
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