Technical description and composition of the TCL L55P65US TV, panel type and modules used. The composition of the modules.
TCL LED
Model: L55P65US
Chassis / Version: MS86R
Panel: LVU550NDEL
LED backlight: 4C-LB5506-HR1
LED driver (backlight): integrated into PSU
PWM LED driver: OB3365RP DIP-16
MOSFET LED driver: TO-252
Power Supply (PSU): L12NW 08-L12NWA2-PW200AA
PWM Power: PWM SOT23-6
MOSFET Power: TO-220
MainBoard: 40-MS86R1-MAA2HG
IC MainBoard: CPU: MSD6586PYET-8-00D9, eMMC: THGBMDG5D1LBAIL, SPI Flash: EN25Q32
Tuner: DVBT / T2 & SAT
Specifications L55P65US
TCL L55P65US
General recommendations for TV LCD LED repair
Possible malfunctions
- The TCL L55P65US TV does not turn on, does not respond to the remote control and control panel buttons, the indicators do not light up or flash.
With similar manifestations, in some cases, the L12NW power supply module is faulty. It is necessary to measure its output voltages, and if they are absent (full or partial), the serviceability of the power switches (TO-220) of the converters and rectifier diodes should be checked for a possible short circuit.
In case of any breakdowns of semiconductors in the secondary circuits, the converter can usually operate normally in an emergency short circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and, less often, the current sensor in the source of the key.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers PWM SOT23-6, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or knowingly working properly.
- There is no image, the screen is black, there is sound, sometimes you can see barely noticeable outlines of the image in the ambient light of the screen.
Usually, in such cases, a malfunction is detected in the LED panel backlight nodes. Often the reason is a malfunction of the LEDs (open circuit, short circuit ...), or connectors of the strips (strings) 4C-LB5506-HR1, less often the LED driver is faulty.
It is impossible to detect an open circuit in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and a voltage of several tens of volts is required to open their junctions. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Usually, Chinese multimeters lightly light up one 3-volt LED if you connect the probes to it in the forward direction (red probe to the anode, black to the cathode). For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or pierced in the K / Z.
If TCL L55P65US has no picture, but there is sound, often the LVU550NDEL display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.
Replacing the LEDs requires disassembling the LVU550NDEL LCD panel - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels
If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But often the main board MainBoard 40-MS86R1-MAA2HG also turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, the fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to trace the passage of LVDS signals from MainBoard 40-MS86R1-MAA2HG with an oscilloscope, as well as synchronizing signals to loops with drivers.
Flooded or unsuccessfully washed screens of LED-TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.
READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.
- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.
Repair or diagnostics of the 40-MS86R1-MAA2HG motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Often the MB (SSB) board needs to be replaced in the event of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - CPU: MSD6586PYET-8-00D9, eMMC: THGBMDG5D1LBAIL, SPI Flash: EN25Q32 and replace the failed chips with new ones. Some malfunctions can be associated with the use of BGA soldering technologies in modern Main Board. Typically, such defects are detected by local heating of the chip.
Malfunction of the DVBT / T2 & SAT tuner is established after checking the software and all supply voltages at its outputs. The data exchange of the tuner with the processor via the I2C bus can be monitored with an oscilloscope.
Users and owners of TVs should remember that attempts to self-repair the TCL L55P65US TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!
Revision after repair of the backlight. OB3365RP. Information from the master.
Reduce the backlight current from 90 mA to 40 mA - on pin 2 (I-SET) of the OB3365RP microcircuit, there are two 39 kOhm and 91 kOhm resistors in parallel in the L12NW power supply. Removed 91 kOhm.
Additional MainBoard Repair
The appearance of the MainBoard 40-MS86R1-MAA2HG is shown in the figure below:
40-MS86R1-MAA2HG
External view of the power supply:
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.
| Name | Part Number | Fabricant | Marking |
|---|---|---|---|
| SG6849 | SG684965TZ | Fairchild / ON Semi | BBxx |
| SG6849 | SG6849-65T, SG6849-65TZ | System General | MBxx EBxx |
| SGP400 | SGP400TZ | 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.
| Name | Part Number | Fabricant | Marking |
|---|---|---|---|
| AP3103A | AP3103AKTR-G1 | Diodes Incorporated | GHL |
| AP8263 | AP8263E6R, A8263E6VR | AiT Semiconductor | S1xx |
| AT3263 | AT3263S6 | ATC Technology | 3263 |
| CR6848 | CR6848S | Chip-Rail | 848H16 |
| CR6850 | CR6850S | Chip-Rail | 850xx |
| CR6851 | CR6851S | Chip-Rail | 851xx |
| FAN6602R | FAN6602RM6X | Fairchild / ON Semi | ACCxx |
| FS6830 | FS6830 | FirstSemi | |
| GR8830 | GR8830CG | Grenergy | 30xx |
| GR8836 | GR8836C, GR8836CG | Grenergy | 36xx |
| H6849 | H6849NF | HI-SINCERITY | |
| H6850 | H6850NF | HI-SINCERITY | |
| HT2263 | HT2263MP | HOT-CHIP | 63xxx |
| KP201 | Kiwi Instruments | ||
| LD5530 | LD5530GL LD5530R | Leadtrand | xxt30 xxt30R |
| LD7531 | LD7531GL, LD7531PL | Leadtrend | xxP31 |
| LD7531A | LD7531AGL | Leadtrend | xxP31A |
| LD7535/A | LD7535BL, LD7535GL, LD7535ABL, LD7535AGL | Leadtrend | xxP35-xxx35A |
| LD7550 | LD7550BL, LD7550IL | Leadtrend | xxP50 |
| LD7550B | LD7550BBL, LD7550BIL | Leadtrend | xxP50B |
| LD7551 | LD7551BL/IL | Leadtrend | xxP51 |
| LD7551C | LD7551CGL | Leadtrend | xxP51C |
| NX1049 | XN1049TP | Xian-Innuovo | 49xxx |
| OB2262 | OB2262MP | On-Bright-Electronics | 62xx |
| OB2263 | OB2263MP | On-Bright-Electronics | 63xx |
| PT4201 | PT4201E23F | Powtech | 4201 |
| R7731 | R7731GE/PE | Richtek | 0Q= |
| R7731A | R7731AGE | Richtek | IDP=xx |
| SD4870 | SD4870TR | Silan Microelectronics | 4870 |
| SF1530 | SF1530LGT | SiFirst | 30xxx |
| SG5701 | SG5701TZ | System General | AAExx |
| SG6848 | SG6848T, SG6848T1, SG6848TZ1, SG6848T2 | Fairchild / ON Semi | AAHxx EAxxx |
| SG6858 | SG6858TZ | Fairchild / ON Semi | AAIxx |
| SG6859A | SG6859ATZ, SG6859ATY | Fairchild / ON Semi | AAJFxx |
| SG6859 | SG6859TZ | Fairchild / ON Semi | AAJMxx |
| SG6860 | SG6860TY | Fairchild | AAQxx |
| SP6850 | SP6850S26RG | Sporton Lab | 850xx |
| SP6853 | SP6853S26RGB, SP6853S26RG | Sporton Lab | 853xx |
| SW2263 | SW2263MP | SamWin | |
| UC3863/G | UC3863G-AG6-R | Unisonic Technologies Co | U863 U863G |
| XN1049 | XN1049, XN1049TP | Innuovo Microelectronics | 49 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.
| Name | Part Number | Fabricant | Marking |
|---|---|---|---|
| AP3105/V/L/R | AP3105KTR-G1, AP3105VKTR-G1, AP3105LKTR-G1, AP3105RKTR-G1 | Diodes Incorporated | GHN GHO GHP GHQ |
| AP3105NA/NV/NL/NR | AP3105NAKTR-G1, AP3105NVKTR-G1, AP3105NLKTR-G1, AP3105NRKTR-G1 | Diodes Incorporated | GKN GKO GKP GKQ |
| AP3125A/V/L/R | AP3125AKTR-G1, AP3125VKTR-G1, AP3125LKTR-G1, AP3125RKTR-G1 | Diodes Incorporated | GLS GLU GNB GNC |
| AP3125B | AP3125BKTR-G1 | Diodes Incorporated | GLV |
| AP3125HA/HB | AP3125HAKTR-G1, AP3125HBKTR-G1 | Diodes Incorporated | GNP GNQ |
| AP31261 | AP31261KTR-G1 | Diodes Incorporated | GPE |
| AP3127/H | AP3127KTR-G1, AP3127HKTR-G1 | Diodes Incorporated | GPH GSH |
| AP3301 | AP3301K6TR-G1 | Diodes Incorporated | GTC |
| FAN6862 | FAN6862TY | Fairchild / ON Semi | ABDxx |
| FAN6863 | FAN6863TY, FAN6863LTY, FAN6863RTY | Fairchild / ON Semi | ABRxx |
| HT2273 | HT2273TP | HOT-CHIP | 73xxx |
| LD7510/J | LD7510GL, LD7510JGL | Leadtrend | xxP10 xxP10J |
| LD7530/A | LD7530PL, LD7530GL, LD7530APL, LD7530AGL | Leadtrend | xxP30 xxxP30A |
| LD7532 | LD7532GL | Leadtrend | xxP32 |
| LD7532A | LD7532AGL | Leadtrend | xxP32A |
| LD7532H | LD7532HGL | Leadtrend | xxP32H |
| LD7533 | LD7533GL | Leadtrend | xxP33 |
| LD7536 | LD7536GL | Leadtrend | xxP36 |
| LD7536R | LD7536RGL | Leadtrend | xxP36R |
| LD7537R | LD7537RGL | Leadtrend | xxP37R |
| LD7539C GL | LD7539C GL | Leadtrend | xxP39C |
| ME8204 | ME8204M6G | MicrOne | ME8204xx |
| NCP1250 | NCP1250ASN65T1G, NCP1250BSN65T1G, NCP1250ASN100T1G, NCP1250BSN100T1G | ON Semiconductor | 25xxxx |
| NCP1251 | NCP1251ASN65T1G, NCP1251BSN65T1G, NCP1251ASN100T1G, NCP1251BSN100T1G | ON Semiconductor | 5xxxxx |
| OB2273 | OB2273MP | On-Bright-Electronics | 73xx |
| R7735 | R7735AGE, R7735HGE, R7735GGE, R7735RGE, R7735LGE | Richtek | |
| UC3873/G | UC3873-AG6-R, UC3873G-AG6-R | Unisonic Technologies | U873 U873G |
Key features of the TCL L55P65US device:
Installed matrix (LED panel) LVU550NDEL.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by the OB3365RP DIP-16 PWM controller. TO-252 switches are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the TCL L55P65US TV is carried out by the L12NW power module, or its analogs using PWM SOT23-6 microcircuits and TO-220 type power switches.
MainBoard - the main board (motherboard) is a 40-MS86R1-MAA2HG module, using CPU chips: MSD6586PYET-8-00D9, eMMC: THGBMDG5D1LBAIL, SPI Flash: EN25Q32 and others.
The DVBT / T2 & SAT tuner provides reception of television programs and tuning to channels.
TV TCL L55P65US with LCD LVU550NDEL, diagonal size 54.6 "(139 cm) 16: 9 format. The brightness of the screen, declared by the manufacturer, 270 cd / m2 is realized by LED backlight. Contrast - the ratio of maximum brightness to minimum , is not less than 4500: 1. The technology of manufacturing the screen of this TV model is realized with LED backlighting.
LVU550NDEL sensor and MainBoard 40-MS86R1-MAA2HG software realize high-quality UHD images at 3840x2160 pixels in 4K UHD, HDR standard. Image processing is implemented using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
L55P65US TV has built-in SMART software and pre-installed Linux Operating System. Internet connection can be made via Wi-Fi wireless connection. Supported media file formats: MP3, WMA, MPEG4, HEVC (H.265), MKV, JPEG.
Speaker power 16 W (2x8 W) is provided by two speakers. Uses the NICAM stereo signal processing system and the Sound Surround function.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, HDMI x2, USB, Ethernet (RJ-45), Wi-Fi. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.
The power supply is 08-L12NWA2-PW200AA.
Dimensions: with stand 1244x780x243 mm, without stand 1244x722x78 mm.
TV weight: with stand: 12 kg
Attention! The LVU550NDEL panel of the TCL L55P65US LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.