Re: LG 50pq3000
The relay clicking all the time (every time i put the TV on) and voltages is 380v without the resistor.
The relay clicking all the time (every time i put the TV on) and voltages is 380v without the resistor.
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Re: LG 50pq3000
The voltage on pin 5 on the IC is 4.8vComment
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Re: LG 50pq3000
So the supply to the micro is fine. I don't know how you would test it since it appears to be a supervisory IC monitoring various signals to control the power supply.Willing to help but I'm no expert.Comment
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Re: LG 50pq3000
It's difficult to see if it works properly but i wonder, can i change it with a new one? or is programmable from the factory (LG).Comment
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Re: LG 50pq3000
Being a micro I can only assume that it is pre-programmed for that set.Willing to help but I'm no expert.Comment
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Re: LG 50pq3000
So with the power supply completely disconnected except for the ac mains, the relay continues to click when power is applied?
The 380v would suggest the pfc is working and getting the vcc2 voltage.
That ic701 is pre programed and not likely the problem.
There are 3 large white ceramic resistors R957 etc. check that they are ok.
Can you read the number on IC801?Last edited by R_J; 03-20-2021, 11:02 AM.Comment
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Re: LG 50pq3000
The relay click once on start up. Resistors are good i check them first. I replace the IC801 already. (L6599D).Comment
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Re: LG 50pq3000
The relay click once every time, i start the TV.Comment
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Re: LG 50pq3000
What is the vcc voltage on Pin 12 of ic801?
What is the voltage on Pin 5?
Why was the ic replaced? was it bad or just a suspect?Comment
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Re: LG 50pq3000
No its not bad l have a new one and checked.
Pin 5 - 0 volts
Pin 12 - 0 volts.Comment
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Re: LG 50pq3000
If you have schematics from this PSU please upload it.Comment
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Hi everyone, over the past few months i have taken a deep dive into motherboard diagnostics and I love the challenge. Currently im trying to learn all about the signals that travel around the motherboard, such as frequencies, enable signals High and Low logic states etc. And i have been learning to read and using the Schematics for this board that i requested here on Badcaps forum, from a few months ago, this is such a great place for these.
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This is A2289, board 820-01987-A. It came in with the screen not working. We could not see any image on the screen, so we ruled out a backlight issue and instead replaced the panel. The display now comes up, but no backlight.
I didn't see any signs of liquid damage, but there was some odd looking spots around U8400. F8400 has voltage on either side of it, and I have 5v present on R8444 and R8445. I did not have 3.2v at R8442 so I figured U8400 was bad, and I replaced it. After replacement, a brief probe to R8442 showed 3.2v so I assumed I had fixed the device. After reassembly however,... -
Hello Sharp TV experts
Our Sharp LC-80LE642U displays one short one long flash error code which is a backlight error. I went into service mode and there were 8 lamp error counts recorded. I reset the count to 0 and did a reset. The last monitor error cause was 16 B00014639:12. 16 is the code for backlight error. I tried to power the tv up but went back into error mode.
> I checked voltages on the power supply board and they all check out .. including 3.28 volts at the error pin.
> There is power to the cpu and T-CONN and no faults found there. The cpu has a flashing...01-24-2025, 11:51 PM -
Hello,
I am strouglling with this TV.
Model: Le40C550J1WXXC and inverter and power suplly BN-4400340B
It boots up normally, but no backligth.
I have check the PFC resistors from 814 to 818 and resolder all of them, I get 380Vdc on the 100uf 450v caps.
I have checked DP803 / ZDM806 / QM801 / ZI802 / QP801 802 / QI801 803
Replaced IPC801 fan7530
All solder joints were checked and also the electrolitics for capacitance and ESR.
I am lost, can someone help me with this issue.
Best regards
Nezoca... -
LG 50PQ3000
Opened this TV and it looked like someone had emptied a hoover bag over all the boards. I cleaned all the boards front and back and noticed the main fuse on the power board had failed. I couldn't see any bad caps so I replaced the fuse and the TV worked with no problems, all voltages were good.
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