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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Sunday 22 December 2019

REPAIRING / SERVICING TV SAMSUNG LE27T51BC

Technical description and composition of the SAMSUNG LE27T51BC TV, panel type and applicable modules. The composition of the modules.
SAMSUNG
Model: LE27T51BC

Chassis / Version: GTR27KE
Panel: V270B1-L01
T-CON: V270B1-L01-C CM2678A-KQ 24C128I P2V16S406TP, LM324AM
Inverter (backlight): DARFON V070
PWM Inverter: OZ960GN, LM399
MOSFET Inverter: FDS8958A
Trans Inverter: 4006A
Power Supply (PSU): PSLF181501A BN96-0258 1A
PWM Power: VIPer12A (Standby), TDA4863G (PFC), F9222L, KIA278, MC33167T
MOSFET Power: 11N60C3
MainBoard: BN41-00636C BN94-00752A PB
IC MainBoard: FLI5921H-LF, 24C32WP, 24C16AN, 25L4005M2C, EM636165TS-6G,
Tuner: TECH0949PG46A (S)
Technical Specifications LE27T51B
SAMSUNG LE27T51BC
General repair guidelines for TV LCD
Repair SAMSUNG LE27T51BC must begin with the diagnosis of the malfunction and a thorough inspection of its external and internal elements, including the case. Many changes visible to the naked eye make it possible to determine the future direction of troubleshooting and localization of the defect. In some cases, faulty elements are visible to the naked eye, for example, charred resistors or swollen metal-ceramic capacitors, or electrolytic in rectifier filters. Ring cracks formed in the soldering of the terminals of transformers or heating elements of the circuit are also frequent sources of many malfunctions with a variety of external manifestations.
If the power supply module BN96-0258 1A malfunctions, the external manifestations may be different, for example, SAMSUNG LE27T51BC does not turn on at all and there is no indication of the indicator lights on the front panel. If the mains fuse is broken in the power supply, in most cases a breakdown of the power switch 11N60C3 is detected, which can be integrated with a PWM controller, or a separate field-effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
If a breakdown of the power switch of the flyback converter of the power supply unit is detected, it should be remembered that it does not fail without any reasons that should be sought by checking other elements of the primary circuit - electrolytic capacitors, PWM controller VIPer12A, TDA4863G, YG972S6, F9222L, KIA278, MC33167T , which can be checked only by replacement, as well as other semiconductor elements (diodes, transistors, zener diodes).
In cases using a power module with an active KKM, troubleshooting is sometimes somewhat more complicated.
If, when you turn on the TV, the image appears and immediately disappears, or is initially absent when turned on, but there are sound and other functions work, there is a high probability of a malfunction of the inverter (power converter for the backlight). In such cases, the lamps, the inverter and the common power module are subject to verification, in which the electrolytic capacitors of the rectifier filter feeding the inverter should be checked.
The operation of the power circuits of the inverter and the backlight in the normal mode are controlled by special protection, which is organized for fire safety, for example, to disconnect during short circuits or breaks in high-voltage connections or when the lamps are depressurized. This protection makes it difficult to diagnose and repair the inverter.
In such cases, the risk of failure of the power elements of the inverter is most likely, and special care is required during work, and after their completion, it is necessary to restore the protection circuit for further safe operation of the TV by the owner in normal mode.
Diagnosis and repair of the motherboard BN94-00752A PB, BN41-00636C is carried out by checking the performance of power stabilizers or updating the software (software). In cases of attempts to repair the MB (SSB) board, it is necessary to check the health of its elements - FLI5921H-LF, 24C32WP, 24C16AN, 25L4005M2C, EM636165TS-6G, which may require replacement with new ones.
Remember! Attempts to self-repair by users of the SAMSUNG LE27T51BC TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
 The appearance of the MainBoard BN41-00636C is shown in the figure below:
BN41-00636C
BN41-00636C can be used in TVs:
SAMSUNG LE27T51B (Panel V270B1-L01 rev c1), SAMSUNG LE27T51BC (Panel V270B1-L01), SAMSUNG LE27T51BX LE27T51BWT (Panel V270B1-L01 Rev c1).
PSU Advanced
The PSLF181501A power module is installed in the LE27T51BC TV using the PFC (Power Factor Correction) circuitry acting as an active filter to eliminate the higher harmonic components of the current consumption. The boost converter based on the TDA4863G PWM controller does not allow the input rectifier filter's electrolytic capacitor to be connected to the network directly through open diodes when the charge current determines its reactance (about 15-30 ohms at a frequency of 50 Hz). As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.

 
The appearance of the power supply
Main features of the SAMSUNG LE27T51BC device:
Installed matrix (LCD panel) V270B1-L01.
The matrix control uses the Timing Controller (T-CON) V270B1-L01-C.
To power the backlight, a DARFON inverter is used, it is controlled by the PWM controller OZ960GN, LM399. A 4006A transformer is installed in the inverter converter. As power elements of the inverter, keys of the FDS8958A type are used.
The necessary supply voltages for all nodes of the SAMSUNG LE27T51BC TV are generated by the PSLF181501A power module or its analogs using VIPer12A (Standby), TDA4863G (PFC), F9222L, KIA278, MC33167T microchips and 11N60C3 type power switches.
MainBoard - the main board (motherboard) is a BN41-00636C module, using chips FLI5921H-LF, 24C32WP, 24C16AN, 25L4005M2C, EM636165TS-6G, and others.
Tuner TECH0949PG46A (S) provides the reception of television programs and tuning to channels.
Information from an alternative source:
SAMSUNG LE27T51BC Chassis GTR27KE
Panel Type (Matrix): V270B1-L01,
Motherboard: BN94-00752A PB, BN41-00636C, FLI5921H-LF, 24C32WP, 24C16AN, 25L4005M2C, EM636165TS-6G x2
T-con: V270B1-L01-C, CM2678A-KQ, 24C128I, P2V16S406TP x2, LM324AM x4
Invertor: DARFON V070, OZ960GN, FDS8958A x8, LM399 x2, LM339, trafo 4006A x7,
PSU: BN96-0258 1A, VIPer12A, TDA4863G, 11N60C3, YG972S6, F9222L, KIA278, MC33167T, MBRFI545CT
Additional technical information about the panel:
Brand: CMO
Model: V270B1-L01
Type: a-Si TFT-LCD, Panel
Diagonal size: 27.0 inch
Resolution: 1366x768, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 596.259x335.232 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 550 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit), CIE1931 75%
Response Time: 8 (G to G)
Frequency: 60Hz
Lamp Type: 14 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V