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 20 April 2020

REPAIR / SERVICING TV DEXP H32B7000K

Technical description and composition of the DEXP H32B7000K TV, panel type and applicable modules. The composition of the modules.
DEXP LED
Model: H32B7000K / B
Chassis / Version: P75-3463GSXV6.0
Panel: HV320WHB-N00
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: P75-3463GSXV6.0
IC MainBoard: CPU: MSD3463GSA, SPI FLASH: MX25L6406E
Appearance
DEXP H32B7000K
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The DEXP H32B7000K TV does not turn on and does not show any signs of turning on, it does not respond to the control buttons or the remote control.
First of all, in such cases, you should verify the operability of the common switching power supply (IIP) - AC / DC voltage converter of the mains voltage. All source elements in this TV model are located on the MainBoard P75-3463GSXV6.0 main board. Then it is necessary to measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of power switches and rectifier diodes of the converters for a possible short circuit.
In case of breakdowns of diodes in the secondary circuits, the converter can operate in emergency short circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key 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 SOT23-6 PWM chips are usually checked by replacing with new ones, or obviously working.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
In such cases, the most likely malfunction of the LED backlight elements. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
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 turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the motherboard P75-3463GSXV6.0 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: MSD3463GSA, SPI FLASH: MX25L6406E. 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.
Attention TV owners! Attempts to self-repair DEXP H32B7000K are not recommended by the manufacturer and can lead to serious negative consequences!
FIRMWARE FOR SPI FLASH  ----------->   DEXP H32B7000K/B , Main: P75-3463GSXV6.0, Panel: HV320WHB-N00

 The appearance of the MainBoard P75-3463GSXV6.0 is shown in the figure below:
P75-3463GSXV6.0
P75-3463GSXV6.0 can be used in TVs:
DEXP F40B7000K (Panel LSC400HN02-G02), DEXP H32B7000K/B (Panel HV320WHB-N00), SUPRA STV-LC32T740WL (Panel HV320WHB-N80).
Main features of the DEXP H32B7000K device:
Installed matrix (LED-panel) HV320WHB-N00.
To power the backlight LEDs, a converter is used, combined with the main board P75-3463GSXV6.0.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a P75-3463GSXV6.0 module, using CPU chips: MSD3463GSA, SPI FLASH: MX25L6406E and others.
Additional technical information about the panel:
Brand: BOE
Model: HV320WHB-N00
Type: a-Si TFT-LCD, CELL
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: ADS, Normally Black, Transmissive
Active Area: 697.685x392.256 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Glass Depth: 0.50 + 0.50 mm
Transmissivity: 6.3% (with Polarizer)
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit)
Response Time: 8 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
Posted By: FRANK at 07:17
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