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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Saturday 21 December 2019

REPAIRING / SERVICING TV SAMSUNG LE20S81BX

Technical description and composition of the SAMSUNG LE20S81BX TV, panel type and applicable modules. The composition of the modules.
SAMSUNG
Model: LE20S81BX LE20S52BP
Chassis / Version: JA20EO GPU20KE
Panel: V201V1-T03
T-CON: V201V1-X3
Inverter (backlight): IP-51135T (V) BN44-00115C
PWM Inverter: MPS0547 MP1038EYS (28)
MOSFET Inverter: SP8K3 730 (8)
Trans Inverter: TG-008 HY0728CC, tc-008 ny0814as
Power Supply (PSU): IP-51135T (V) BN44-00115C
PWM Power: DM07652R
MainBoard: BN41-00925A
IC MainBoard: TDA15021H / N1B80, TSU396AWJ, TDA7266D, TDA7058, LCX14
Tuner: BN40-00077A - TECH0849PG31B (S)
Control: Remote: BN59-00437A, IR: BN41-00931A
Appearance
SAMSUNG LE20S81BX
General repair guidelines for TV LCD
It is advisable to start repairing the SAMSUNG LE20S81BX or LE20S52BP TV with an examination of the internal and external elements. In some cases, visible external damage to the elements can suggest directions for troubleshooting and localizing the defect before starting the necessary measurements at the control points of the nodes of electronic circuits. Carbonized paint on the upper layer of resistors, electrolytic capacitors of rectifier filters deformed after boiling, cracked soldering on the terminals of the elements can often tell the cause of the defect and possible consequences.
Failures of the IP-51135T (V) or BN44-00115C power supply module can be expressed in different ways, for example, the TV does not turn on at all and the control lamps on its front panel do not light up and do not blink, there are no signs of operability. It is advisable to start the troubleshooting of the power supply module by checking the mains fuse. If it is torn, it is necessary to check first of all the power semiconductor elements - rectifier diodes and the power switch of the converter, which are often found in breakdown conditions in such situations.
Power switches in flyback converters fail extremely rarely for no reason and, if they are broken, it is necessary to look for a malfunction in the stabilization circuits by checking electrolytic capacitors, semiconductor devices, and resistors in the primary circuit. The reason may be a malfunction of the PWM controller microchip DM07652R, which can only be checked by replacing it with a new or obviously working one.
When using a power factor correction unit (PFC) in the power modules, troubleshooting becomes somewhat more complicated and requires additional experience and knowledge of the device for their operation.
If the SAMSUNG LE20S81BX or LE20S52BP TV does not have an image, but there is sound, the malfunction should be sought in the backlight lamp power converter (inverter). It is also necessary to check the serviceability of the electrolytic capacitors of the filter of the secondary rectifiers of the BP (power supply) for an overstated ESR.
Diagnostics of an IP-51135T (V) or BN4400115CSE inverter can be difficult due to the protection being triggered, which is organized by the designers to prevent negative consequences or fires in emergency cases, for example, during short circuits or breaks in the lamp power supply circuit, as well as their possible leakage. To make the necessary measurements at control points or to take the necessary waveforms, repairmen have to block the protection circuits in order to be able to diagnose.
In these cases, special care must be taken in view of the risk of failure of the power elements. After completing all repair work, it is imperative to restore the protection circuits for full and safe further operation of the TV by the user.
On the BN41-00925A motherboard, in case of a malfunction, you should first check the operation of the power supply stabilizers of the microcircuits and, if necessary, update the software (software). In some cases, it is necessary to check or replace (if necessary) the elements of the MB board (SSB) - TDA15021H / N1B80, TSU396AWJ, TDA7266D, TDA7058, LCX14.
Owners and users of SAMSUNG LE20S81BX and LE20S52BP TVs need to remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!


The appearance of the MainBoard BN41-00925A is shown in the figure below:
BN41-00925A
The appearance of the power supply
Main features of the SAMSUNG LE20S81BX device:
Installed matrix (LCD panel) V201V1-T03.
The matrix control uses the Timing Controller (T-CON) V201V1-X3.
An IP-51135T (V) inverter is used to power the backlight lamps; it is controlled by the MPS0547 MP1038EYS PWM controller (28). The transformer TG-008 HY0728CC, tc-008 ny0814as is installed in the inverter converter. As power elements of the inverter, keys of the type SP8K3 730 (8) are used.
The necessary supply voltages for all nodes of the TV SAMSUNG LE20S81BX are generated by the IP-51135T power supply module or its analogs using DM07652R microcircuits.
MainBoard - the main board (motherboard) is a BN41-00925A module, using TDA15021H / N1B80, TSU396AWJ, TDA7266D, TDA7058, LCX14 and others.
Tuner BN40-00077A - TECH0849PG31B (S) provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: CMO
Model: V201V1-T03
Type: a-Si TFT-LCD, Panel
Diagonal size: 20.1 inch
Resolution: 640x480, VGA
Display Mode: TN, Normally White, Transmissive
Active Area: 408x306 mm
Surface: Antiglare
Brightness: 500 cd / m²
Contrast Ratio: 600: 1
Display Colors: 262K (6-bit), CIE1931 75%
Response Time: 3/5 (Tr / Td)
Frequency: 60Hz
Lamp Type: 6 pcs CCFL Without Driver
Signal Interface: TTL (1 ch, 6-bit), 50 pins
Voltage: 5.0V (VCC)
Posted By: FRANK at 08:32
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