Thank you for confirming the part number. But can you explain why it is shorting out immediately? I just don't understand why there's a transistor to pull the input to 16V_F while the input is only rated at 7 volts.
The schematic matches the board. And effectively I measure 5 volts at pin 5 VCC and 16 volts at pin 2 IN_A. Does it mean that this is a design flaw? Or that Q16702 is not supposed to be turned on?
Maybe I'm wrong to assume that 16V_F is 16 volts in reference to VAD. Can someone confirm?
Another question, can someone explain me why the base...
Yanleb
Senior Member
Last Activity: 04-09-2024, 10:33 PM
Joined: 05-06-2017
Location: Longueuil, QC
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Panasonic TC-P50G25 SC board TNPA5081AF shorting again after repair
Hi all,
After repairing my TNPA5081AF, it shorts out immediately after powering it.
I traced down the problem to the SOT23-5 Inverter IC773 (marked HA on its case, and IC16773 on the schematic). The chip receives a supply voltage of 5 volts but it receives 16 volts on its input. This is what I measure on the board, and this is also what I see on the schematic.
I think that I found the data sheet of the IC773 chip. It should be a TC7SH14F. Its max input voltage is 7 volts. This is not a surprise that the chip will short out when it receives 16 volts on... -
LG 60PK550 Logic Control Board EBR63450301
Hi all, I just want to share the repair of my 60PK550-UA TV set.
The TV set was powering on, just no image. After verification, nothing wrong on the YSus or ZSus boards. Nothing wrong on the main board either.
But I noticed that the LED was not flashing on the Logic Control Board. This is an EBR63450301. The LED is supposed to flash even with all the flat cables disconnected, with only the power cable attached.
All the voltages measured at the electrolytic capacitors on the board were good. From top left to bottom right:
C57: 3.30V
C61:... -
Panasonic part number in service manuals
In the Panasonic service manuals, both in the board schematics and in the part listing, the part numbers that are given are Panasonic part numbers instead of the actual part numbers.
This is especially annoying for small SMD components like diodes and transistors when you only have 1-3 digits printed on the component body.
For an example, look at the attached PDF.
Do you have a way to cross reference the Panasonic part number with the actual part number?
Thanks.... -
Re: Samsung UN58TU7000F no picture
I would agree, but why is the voltage missing even with the flex cable disconnected?Leave a comment:
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Samsung UN58TU7000F no picture
I have a Samsung UN58TU7000FXZC (same as UN58TU7000FXZA, just the Canadian model) with no picture. Backlight is on and sound is coming out just fine. Just no picture.
What is frustrating is that there's no voltage test point and no component labelling of any kind.
What I have found so far:
1. No voltage at pins 91-94 of the 96 pins connector CN1300 (marked 1 on the picture). This TV set has no T-CON board. The 96 pin flex cable goes directly to the right (when facing TV) lower panel board. Itself is linked with another flex to the other side.
2. Voltage... -
Re: Hisense 58R6009 T-Con board shorted chip
From the spec sheet I linked can you lead me to that i2c communication? I've looked without success.Leave a comment:
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Re: Hisense 58R6009 T-Con board shorted chip
A Main Board Tester. This is an interesting device. I didn't know it exists.
I've already disconnected the flat cable going from the T-Con board to the shorted side of the panel. Still no picture.
As I said, the main board doesn't send a signal to the T-Con Board through the LVDS cable. Even with the LVDS cable disconnected between the main board and the T-Con board I don't see any kind of signal using my 200MHz oscilloscope.
I wanted to know if there's any kind of error reporting or feedback from...Leave a comment:
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Re: Hisense 58R6009 T-Con board shorted chip
Hi all. I returned working on this TV set after leaving it on the side for 5 weeks. When I powered it ON I saw smoke coming from one of the COF. And yeah, short on the 1.8 volt line. The panel is now trash.
I've ripped off the flex cable from its board to remove the short and it restored the 1.8 volt line. Still no picture. Using a 200MHz scope I see no activity at all going to the LVDS cable. I tried with the T-Con board disconnected from the panel, and with the T-Con board disconnected from the main board. Still no signal...Last edited by Yanleb; 09-23-2022, 09:26 PM.Leave a comment:
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Re: Hisense 58R6009 T-Con board shorted chip
Yeah you are right. Don't forget that my initial question was about compatibility of the two chips. Here is a picture of my problem.
And what about my question? Do you know why cutting lines between the T-Con board and the LCD panel makes them work again?...Last edited by Yanleb; 08-16-2022, 06:37 PM.Leave a comment:
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Re: Hisense 58R6009 T-Con board shorted chip
Of course all the power circuitry has been checked.
But I've been able to find a used T-Con board for 9$. The seller had two. Since the shipping was 30$ which is high compared to what he was asking for the board, I bought the two.
Same problem with the 3 boards. Screen only displays washed out vertical lines. All the voltages on the two screen bottom boards have been checked.
I've seen a few videos on youtube showing people masking some traces on the ribbon connector between the T-Con board and the...Leave a comment:
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Re: Hisense 58R6009 T-Con board shorted chip
Soldering of the chip has been done under a microscope. I already checked for shorts and loose pins.
When double checking the test points I can see a missing 3.3 volt. I'll address that.Leave a comment:
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Hisense 58R6009 T-Con board shorted chip
Hi, I'm working on a Hisense 58R6009 with a bad T-Con board. InnoLux T-Con board model MACDJ4050 (BVLC0A6AH394104PB00001). The LCD screen was displaying only washed out vertical lines.
The main chip, an INX IN8208A EN2, was heating a lot. The only replacement I found is an IN8208A N2.
After replacement the chip doesn't heat as before, but now I'm stuck with a completely black screen.
My question is: Is the IN8208A N2 compatible with the IN8208A EN2?
Thanks. -
Re: Schematic or datasheet for Plasma TV buffer chip
Thank you Biruslapio. The ST datasheets are a real gold mine of information. This is strange I never seen a ST chip in a plasma TV.
And thank you Iotas. The Panasonic chip pinout will be useful. This is very very stange. The datasheet of the Panasonic AN16021 is an exact copy of the SN755870KPZT that Biruslapio sent.Leave a comment:
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Re: Schematic or datasheet for Plasma TV buffer chip
Thank you Biruslapio. I've never seen this chip. Usually what I see are Renesas and Panasonic chips. I was not aware that TI was making them also.
For sure it will help me to learn. Thanks again.Leave a comment:
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Schematic or datasheet for Plasma TV buffer chip
Hi all,
I'm interested in understanding how a buffer board chip is working. I know there's about 90 outputs per chip to the plasma panel, but I'm more interested to know about the input pins. I guess that some of them are address pins, but I want to know more.
So far I've found nothing at all. I haven't found any datasheet about the various buffer chips, and I haven't found any schematic for the buffer board using them (Y Buffer Board in Samsung's terminology).
Any information will make me happy. It can be from any buffer chip or plasma TV manufacturer.... -
Re: Vizio M70-D3 4K with dark spots backlight issue
Repair finished. I ended up removing all the problematic connectors and as I said hard wiring the LED strips. I've attached pictures of the repair.
All connectors have been removed. All the LED strip ends near the green power distribution boards have been glued to the back panel (only one side of the LED strip, where the connectors were located). Solid wires have been soldered directly on the boards. I even put wires on the pads that secured the connectors for added rigidity.
The result is obvious....Leave a comment:
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Vizio M70-D3 4K with dark spots backlight issue
I have a Vizio M70-D3 4K with a dark spots backlight issue. It is using the Y8387248A backlight driver board.
On this model each of the 64 transistor powers 2 LEDs. Using my TKDMR TD3H backlight tester I've determined that the backlight LED strips were the issue, and the backlight driver board was just fine. Some LED pairs required 5.9 volt at 155mA, some required 9.5 volt and some were completely open.
I've removed the LCD panel and once the LED strips were exposed I've tested them again by connecting my LED tester directly on the test pads. To my surprise all, I've... -
Samsung 4K UN55NU7100F stuck in a reboot loop
Ok, I have this Samsung 4K UN55NU7100F that is stuck in a reboot loop.
I know this is not a backlight issue since when I disconnect the power cable from the main board the power supply starts and the backlight is working just fine. Each of the 6 LED strip connectors measure 116 volts.
I've found that when I disconnect any one of the two LVDS cables going from the main board to the LCD panel (it doesn't have a T-CON board) it is working just fine (with no picture as you can expect).
On a few occasions I found that reconnecting the disconnected LVDS... -
Re: sharp LC40ELE 600E standby only faulty backlight
Some of you don't understand that you cannot access the service menu if the TV set refuses to power on due to the lamp error. After getting the lamp error 5 times it locks down indefinitely. In that case all the key combinations you can read in the service manuals will just not work.
In my case the LED strips were repaired but it has been impossible to bring the service menu to reset the lamp error. An oscilloscope in single trigger mode on the LED driver circuit proved that.
The TV doesn't have a crystal...Leave a comment:
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