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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All posts are presented here for informative, historical and educative purposes as applicable within fair use. NOTHING HERE IS FOR SALE !

Sunday, 3 January 2021

REPAIRING / SERVICING TV TELEFUNKEN TF-LED32S52T2S

 Technical description and composition of the TELEFUNKEN TF-LED32S52T2S TV, type of panel and modules used. Module composition.

TELEFUNKEN LED
Model: TF-LED32S52T2S

Chassis/Version: MSA6285-ZC01-01

Panel: LSC320AN09-H

LED driver (backlight): integrated into MainBoard

PWM LED driver: AP3064 // OB3350

MOSFET LED driver: TO-252

Power Supply (PSU): integrated into MainBoard

PWM Power: PWM SOT23-6

MOSFET Power: SMK0870F

MainBoard: MSA6285-ZC01-01

IC MainBoard: CPU: MSD6A628VX, SPI Flash: MX25L4006E, DC-DC: MSH6000A, RT7240

Specifications: NoName

TF-LED32S52T2S Specifications
TELEFUNKEN TF-LED32S52T2S
General advice about LCD LED TV repair
Possible faults

- TELEFUNKEN TF-LED32S52T2S TV set will not turn on or show any signs of trouble. No response to remote control or front panel control.

The trouble in such cases first of all shall be sought in the power elements of switching power supply (PPS) - AC/DC converter, which is combined with the MainBoard MSA6285-ZC01-01 in this TV model. It is necessary to measure its output supply voltages, and in case of their absence to check the operability of power keys (SMK0870F) of converters and rectifier diodes for the probability of breakdown in semiconductor PN-junctions.
If the diodes in the secondary circuits breakdown, the inverter may operate in emergency short-circuit mode without output voltages, and if the primary circuit power elements are shorted, the mains fuse and/or the current sensor at the source of the switch is usually blown.
The breakdown of power switches (MosFet) in switching supplies is sometimes caused by faults in other circuit elements, e.g. in the circuits supplying the PWM controller, the frequency pickup or damping circuits, as well as in the negative feedback (NF) stabilisation circuits. PWM regulators (PWM) PWM SOT23-6, unless they have visible housing damage and outright short circuits between pins, are usually checked by replacement.

- No picture, but there is sound and reaction to remote control commands. Or the image appears immediately after switching on and then disappears.

As a rule, in this case the LED panel backlight is defective. Often the cause is a breakage of the LEDs, or poor contact in the connectors plates, less often faulty can be the LED-driver.
It should be remembered that to determine the breakage in the LED line without disassembling the panel, using a tester or multimeter is not possible without an additional device, such as a current source. It may take several tens of volts to open all PN junctions connected in series at once. Then it is necessary to open the panel and check each LED separately with a multimeter. If the capacity of your multimeter does not allow to open the LED in the forward direction or twin LEd's are used, then the PN junction of the faulty stabiliser can indirectly be an indication of the functionality. If the LED is faulty, the PN junction of the stabiliser will either be open or shorted.

- The LED blinks or lights constantly, the TV does not switch on, the remote control is unresponsive.

Repair or diagnostic of MSA6285-ZC01-01 motherboard should start with checking stabilisers and power converters required for powering the microcircuits and matrix. Software (software) should be updated or replaced if necessary. Complex repair of MB board (SSB) is possible in some cases and practiced by repairers. You should check and if necessary replace CPU: MSD6A628VX, SPI Flash: MX25L4006E, DC-DC: MSH6000A, RT7240. BGA chip faults are usually easy to detect by warming up.

If the TV works normally from external devices, but does not tune to the TV channels, the NoName tuner might be faulty. In these cases you should first check that there is a supply voltage to the corresponding pins. Also make sure that the tuner and processor are communicating via the I2C bus. Sometimes a software malfunction can be the cause of a malfunction.

Attention TV Owners! Attempting to repair your TELEFUNKEN TF-LED32S52T2S by yourself is not recommended by the manufacturer and may cause serious damage.

DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    Chassis MSA6285-ZC01-01.


 Warning. If there is an OB3363QP chip in the driver, take your time to verify it, it is most likely a mislabelled AP3064. A schematic  is attached. Compare the documentation of both microcircuits.

Information from the laboratory.
Reduce backlight current from 450 mA to 320 mA - I removed 120 kOhm and left 47 kOhm at the ISET input of the AP3064 driver (pin 2) on the MSA6285-ZC01-01 board.

Limit the current to the driver. MSA6285-ZC01-01 and AP3064. General information

The driver may use the OB3350 chip. Then you can reduce the driver current with low impedance resistors in the LED circuit from the LED connector pins.


You can read more below:

Many TV manufacturers are now installing a questionable thermal rating for the backlight LEDs, which has a negative effect on the longevity of the device. In half of the cases, LEDs fail after 2-3 years of operation due to overheating, usually seen by the destroyed phosphor on the body of the LEDs. The warranty period, as a rule, the LEDs still have time to work out.

Even if the maximum allowable current is within specifications the cooling of LEDs is not always sufficiently efficient, which can be seen by the traces of overheating, i.e. dark spots on textolite slats on the back side. And modern LED televisions use diodes with an external phosphor coating, which after a year or two crumbles and the crystal directly shines purple. How such a source of ultraviolet radiation can harm the health of users, no one has yet thought.

Chinese manufacturers via Aliexpress supplies diodes and LED strips in kits of any assortment, but the lucky owner of the TV pays for them and for the repair.

After replacing one or more faulty LEDs, it is useful to look at the rest carefully, if the phosphor is cracked, it is advisable to replace all the LEDs. If you measure the voltage drop on overheated LEDs, it will be slightly higher than that of adjacent less worn or new LEDs, which indirectly indicates the presence of a parasitic active resistance (ESR). Further operation of such LEDs is even more questionable.


If you reduce the current in the diodes, the power dissipation and the real operating temperature will decrease, then there is a chance that the old ones will still work.


Ways to limit the current in LED backlight drivers:

There is a lot of information on the Internet about ways to limit the current in the LED backlighting for different TVs and LED drivers. A lot of it is written plausibly but sometimes it is written by people far from electronics in order to publish any popular content on hot topics to boost web-sites ratings.

It's impossible to talk about each case separately within one article, because even similar models may have different panels and different boards with their own driver variants. But there are basic principles that are clear to craftsmen with even minimal knowledge and skill.


Other popular, complex and controversial current limit cases will be published as information becomes available.
There are three basic ways to reduce the backlight current.

1. By increasing the resistance of the LED current sensor - a low-resistance measuring resistor in the cathode (LED-) circuit.
2. Increasing the ratings of the resistors on the ISET (current setting) input of the LED driver chip.
3. changing the resistor ratings in the divider on the ADIM (Dimming) control input.

The fundamental difference between input ISET and ADIM is that ISET - input inverted, as FB, and ADIM - direct.



To reduce the backlight current in LED drivers with AP3064 controller, increase the total resistance of the Rset resistor connected to pin 2 of ISET AP3064 relative to the housing. Calculated current value according to the documentation I[mA] = 1200/Rset[kOm].

If the LED driver chip is marked as OB3363QP - this is somebody else's mistake. In reality and according to the schematic it should be AP3064.

DOWNLOAD SCHEMATIC DIAGRAM  LED drivers  ----------->    AP3064

DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   --------->   Chassis MSA6285-ZC01-01


The appearance of the MainBoard MSA6285-ZC01-01 is shown in the figure below:

MSA6285-ZC01-01




Main features of the TELEFUNKEN TF-LED32S52T2S:

A matrix (LED panel) LSC320AN09-H is installed.
A converter combined with MSA6285-ZC01-01 main board, controlled by AP3064 // OB3350 PWM controller, is used to power the backlight LEDs. A TO-252-type switch is used as a power element in the LED driver.
The power module is combined with MainBoard and is designed as reverse-going AC/DC converter using PWM SOT23-6 chips and SMK0870F-type power switches.
MainBoard - motherboard is MSA6285-ZC01-01 module, with CPU: MSD6A628VX, SPI Flash: MX25L4006E, DC-DC: MSH6000A, RT7240 and other microchips.
The NoName tuner provides TV programme reception and channel tuning.

 

PWM SMPS in SOT-23-6, SOT-26, TSOP-6 packages

In the circuitry of modern switching power supplies (SMPS), PWM controllers made in small-sized planar packages with six terminals have gained wide popularity. The enclosure type designation can be SOT-23-6, SOT-23-6L, SOT-26, TSOP-6, SSOT-6. The appearance and arrangement of the pins are shown in the figure below. In this case, the code marking LD7530A is shown on the left fragment of the picture.


 

 Pin assignment:
1 - GND. (Common wire).
2 - FB. (FeedBack - Feedback). Input for controlling the duration of pulses with a signal from the output voltage. Sometimes it can be labeled COMP (input comparator).
3 - RI / RT / CT / COMP / NC - Depending on the type of microcircuit, it can be used for a frequency-setting RC circuit (RI / RT / CT), or for organizing protection, as an input of a PWM trip comparator at a threshold value at its input, specified in the document. In some types of microcircuits, this input may not be used in any way (NC - No Connect).
4 - SENSE, otherwise CS (Current Sense) - Input from the current sensor at the source of the key.
5 - VCC - Input voltage supply and start of the microcircuit.
6 - OUT (GATE) - Output for controlling the gate (Gate) of the key.

Functionally, these regulators work on the principle of the previously popular xx384x PWM microcircuits, which have proven themselves well in terms of reliability and stability.

Some difficulties often arise when replacing or choosing an analog for such PWM regulators due to the use of code markings in the designation of the type of microcircuits. The situation is complicated by a large number of component manufacturers who do not always provide documentation to the mass access, just as not all manufacturers of finished devices supply repair service centers with diagrams, so repairmen often have to study real circuit solutions by installed components and wiring connections directly on the board.

In practice, PWM microcircuits and the marking code EAxxx and Eaxxx are often found. Official documentation for them was not found in the public domain, but discussions on the forums and pieces of pictures from PDF from System General, which publishes them as SG6848T and SG6848T2, have survived. The drawing is here placed left .


 

For the attention of the masters, here below are PDF datasheet tables compiled from information available on the Internet and PDF documents for the selection of analogues types when replacing the most common six-legged planar PWM with pinout pins: pin1 - GND, pin2 - FB (COMP), pin4 - Sense, pin5 - Vcc, pin6 - OUT ...
Their main difference is the application and purpose of pin 3. 

 

NamePart NumberFabricantMarking
SG6849SG684965TZFairchild / ON SemiBBxx
SG6849SG6849-65T, SG6849-65TZSystem GeneralMBxx EBxx
SGP400SGP400TZ System General AAKxx

 

 PWM controllers (PWM) with a 95-100 kOhm resistor on pin 3.

When applying the PWM listed below, the frequency should be set with the RT (RI) resistor from pin 3 to ground. Usually its nominal value is chosen 95-100 kOhm for a frequency of 65-100 KHz. For more details, see the here below attached documentation. PDF files are packed in RAR.

 

NamePart NumberFabricantMarking
AP3103AAP3103AKTR-G1Diodes IncorporatedGHL
AP8263AP8263E6R, A8263E6VRAiT SemiconductorS1xx
AT3263AT3263S6ATC Technology3263
CR6848CR6848SChip-Rail848H16
CR6850CR6850SChip-Rail850xx
CR6851CR6851SChip-Rail851xx
FAN6602RFAN6602RM6XFairchild / ON SemiACCxx
FS6830FS6830FirstSemi
GR8830GR8830CGGrenergy30xx
GR8836GR8836C, GR8836CGGrenergy36xx
H6849H6849NFHI-SINCERITY
H6850H6850NFHI-SINCERITY
HT2263HT2263MPHOT-CHIP63xxx
KP201
Kiwi Instruments
LD5530LD5530GL LD5530RLeadtrandxxt30 xxt30R
LD7531LD7531GL, LD7531PLLeadtrendxxP31
LD7531ALD7531AGLLeadtrendxxP31A
LD7535/ALD7535BL, LD7535GL, LD7535ABL, LD7535AGLLeadtrendxxP35-xxx35A
LD7550LD7550BL, LD7550ILLeadtrendxxP50
LD7550BLD7550BBL, LD7550BILLeadtrend xxP50B
LD7551LD7551BL/ILLeadtrendxxP51
LD7551CLD7551CGLLeadtrendxxP51C
NX1049XN1049TPXian-Innuovo49xxx
OB2262OB2262MPOn-Bright-Electronics62xx
OB2263OB2263MPOn-Bright-Electronics63xx
PT4201PT4201E23FPowtech4201
R7731R7731GE/PERichtek0Q=
R7731AR7731AGERichtekIDP=xx
SD4870SD4870TRSilan Microelectronics4870
SF1530SF1530LGTSiFirst30xxx
SG5701SG5701TZSystem GeneralAAExx
SG6848SG6848T, SG6848T1, SG6848TZ1, SG6848T2Fairchild / ON SemiAAHxx EAxxx
SG6858SG6858TZFairchild / ON SemiAAIxx
SG6859ASG6859ATZ, SG6859ATYFairchild / ON SemiAAJFxx
SG6859SG6859TZFairchild / ON SemiAAJMxx
SG6860SG6860TYFairchildAAQxx
SP6850SP6850S26RGSporton Lab850xx
SP6853SP6853S26RGB, SP6853S26RGSporton Lab853xx
SW2263SW2263MPSamWin
UC3863/GUC3863G-AG6-RUnisonic Technologies CoU863 U863G
XN1049XN1049, XN1049TPInnuovo Microelectronics49 xxx

 

 PWM controllers that use pin 3 differently.

When using the following PWM (PWM controllers), you should pay attention to pin 3, which can be used to organize protection - thermal or from overvoltage of the input voltage.
The frequency can be fixed at 65kHz, or set by the value of the capacitor at pin 3.
When replacing any microcircuits with analogs, carefully study the documentation. PDF files are packed in a RAR archive.

 

NamePart NumberFabricantMarking
AP3105/V/L/RAP3105KTR-G1, AP3105VKTR-G1, AP3105LKTR-G1, AP3105RKTR-G1Diodes IncorporatedGHN GHO GHP GHQ
AP3105NA/NV/NL/NRAP3105NAKTR-G1, AP3105NVKTR-G1, AP3105NLKTR-G1, AP3105NRKTR-G1Diodes IncorporatedGKN GKO GKP GKQ
AP3125A/V/L/RAP3125AKTR-G1, AP3125VKTR-G1, AP3125LKTR-G1, AP3125RKTR-G1Diodes IncorporatedGLS GLU GNB GNC
AP3125BAP3125BKTR-G1Diodes IncorporatedGLV
AP3125HA/HBAP3125HAKTR-G1, AP3125HBKTR-G1Diodes IncorporatedGNP GNQ
AP31261AP31261KTR-G1Diodes IncorporatedGPE
AP3127/HAP3127KTR-G1, AP3127HKTR-G1Diodes IncorporatedGPH GSH
AP3301AP3301K6TR-G1Diodes IncorporatedGTC
FAN6862FAN6862TYFairchild / ON SemiABDxx
FAN6863FAN6863TY, FAN6863LTY, FAN6863RTYFairchild / ON SemiABRxx
HT2273HT2273TPHOT-CHIP73xxx
LD7510/JLD7510GL, LD7510JGLLeadtrendxxP10 xxP10J
LD7530/ALD7530PL, LD7530GL, LD7530APL, LD7530AGLLeadtrendxxP30 xxxP30A
LD7532LD7532GLLeadtrendxxP32
LD7532ALD7532AGLLeadtrendxxP32A
LD7532HLD7532HGLLeadtrendxxP32H
LD7533LD7533GLLeadtrendxxP33
LD7536LD7536GLLeadtrendxxP36
LD7536RLD7536RGLLeadtrendxxP36R
LD7537RLD7537RGLLeadtrendxxP37R
LD7539C GLLD7539C GLLeadtrendxxP39C
ME8204ME8204M6GMicrOneME8204xx
NCP1250NCP1250ASN65T1G, NCP1250BSN65T1G, NCP1250ASN100T1G, NCP1250BSN100T1GON Semiconductor25xxxx
NCP1251NCP1251ASN65T1G, NCP1251BSN65T1G, NCP1251ASN100T1G, NCP1251BSN100T1GON Semiconductor5xxxxx
OB2273OB2273MPOn-Bright-Electronics73xx
R7735R7735AGE, R7735HGE, R7735GGE, R7735RGE, R7735LGERichtek
UC3873/GUC3873-AG6-R, UC3873G-AG6-RUnisonic TechnologiesU873 U873G

 

 


TELEFUNKEN TF-LED32S52T2S LCD TV LSC320AN09-H measuring 31.5" (80cm) diagonally in 16:9 aspect ratio. 330 cd/m² screen brightness is provided by an LED backlight. Contrast, as the ratio of maximum brightness to minimum brightness, is 5000:1. The screen technology of this TV model features LED backlighting.
The LSC320AN09-H matrix and MainBoard MSA6285-ZC01-01 software realize an HD picture quality of 1366x768 resolution in 720p (HD Ready).
The TF-LED32S52T2S comes with SMART Software and preinstalled Android OS. Internet connection can be established via Wi-Fi. Supports media formats: MP3, MPEG4, Xvid, MKV, JPEG.
The 10W (2x5W) sound system is powered by two speakers. NICAM STEREO audio processing system is used.
External interface (connection with other devices) is supported by standard inputs and outputs: antenna input (RF), AV, HDMI x2, USB x2, Ethernet (RJ-45), Wi-Fi. There is a headphone output. The digital tuner receives DVB-T, DVB-T2, DVB-C TV channels.

The power supply is used as part of the MainBoard.

Dimensions: With stand 731x481x200mm, without stand 731x433x70mm.

TV weight: 4.9kg.

Warning. The LSC320AN09-H bezel of your TELEFUNKEN TF-LED32S52T2S LED TV is an expensive and fragile part of the TV.
Avoid all impacts to the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also not safe to get liquids on the screen. Sometimes a single drop is enough if it drips down the glass onto the cables and the television becomes unrepairable.