I've managed to get the exact same model (in working condition) for cheap on marketplace and did the following to help troubleshooting:
1. take out working mainboard and put into non working TV => issue still present, TV doesn't turn on, standby LED wouldn't flash anymore but stay solid
2. take out working power supply and put into non working TV => TV turns on and works
3. take out working mainboard and replace with mainboard that was inside in the first place => TV turns on and works.
this means the problem is within the power supply board which...
mar1in
Member
Last Activity: 11-28-2024, 06:17 PM
Joined: 09-07-2023
Location: Melbourne
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The reason why I think they are shorted is because the ones next to them that are same or similar size have 3-5k value of resistance.
but I've heard that resistors are not really failing, its most likely other components. I'm quite a beginner in troubleshooting but I have skills to replace parts of the board. I just recently bought a hot air station, might try an cpu reflow and see how that goes.Leave a comment:
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Actually, I found 3 resistors shorted in the marked area. R8117, R8118 and R8028.
Need to check for a service manual to see if I can get those parts, or do you think there will be more shorted components than just those resistors ?Leave a comment:
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I have had a Quick Look and couldn't find any shorted ones, I will try again but the next step might be reflow/resoldering the cpu, or what do you think?Leave a comment:
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actually there is no tcon boardLeave a comment:
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thanks, will check the TCON fuse when I get a chance.
sorry, should have posted some pics.
there are 5x 13.2V lines, each of them I'm getting 11.8V, is that because it's not yet powered on fully?...Leave a comment:
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LG UH652T doesn't turn on and stands is blinking once a second
Hi everyone,
I've got this LG TV here that wouldn't turn on and be stuck in a standby loop (blinking red once every other second).
Did test the following:
* LED's seem fine as they all light up using LED Tester
* Power Supply supplied around 111V for each LED Strips (2x edge lid strips)
* PWR_ON would be at around 3V but dropping every other second (just like the standby light)
* DRV_ON is doing the same
* power supply has a green LED onboard, but that doesn't seem to do anything (stays off the whole time).
* there is a tiny clicking... -
Samsung TU8000, backlight and sound on, stuck in blue screen
Hi everyone,
I've got this Samsung here that would be stuck in a boot loop.
After opening up and doing the tape block method, I was able to get it to turn on and play sound from the HDMI input, but with a blue screen.
Does that mean there is another combination of pins that I need to block in order to get a picture, or is there something more serious, faulty mainboard or faulty panel?
Thanks in advance -
Re: Fix broken tinsel wire on Speaker
thanks guys, i managed to fix it temporarily, but probably needs replacing tinsel wire soon.Leave a comment:
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Fix broken tinsel wire on Speaker
Hi everyone,
I've saved a pair of Philips AH 495 speakers from landfill and diagnosed the woofers are not working due to a loose or broken tinsel wire just on the joint of the cone (left wire on the picture)
What's the best and easiest way to fix this without damaging the cone ?
Can this be simple soldered on?... -
Re: Panasonic TH-55AS670A no picture no sound
at this stage the best i can do IMO is to look for a spare mainboardLeave a comment:
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Re: Panasonic TH-55AS670A no picture no sound
ok, there is no easy fix for a hobbyiest like me i guess.
i have to measure again but i think the multimeter showed something above 100V on two pins, 16V and 5V and 1V and 0.8V on the others...Leave a comment:
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Re: Panasonic TH-55AS670A no picture no sound
i've just measured the pins of IC5300, see image attached.
doesn't matter if TV is in standby or turned on, there is only 16V on one pin, the others are all 0V.
does that indicate a fauly IC ?
the other IC8705 has Voltages (from 0.8V to 120V) on almost every pin except one....Leave a comment:
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Re: Panasonic TH-55AS670A no picture no sound
ok that's interesting, how would I do this, using a jumper wire ?...Leave a comment:
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Re: Panasonic TH-55AS670A no picture no sound
i was just wondering, should there be a clicking sound (for a relay ?) when you turn on the TV, because this one seems to be doing no clicking.
Just realised, because I had a look at a similar model of Panasonic the other day and there was a clicking sound once turned on.
That would indicate a problem with the power supply board, but in my case I measured most of the test points with valid voltages.
If I understand it correct, it could be something with the LED driver that is also on that same board?Leave a comment:
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Re: Panasonic TH-55AS670A no picture no sound
is there any way to reflash via USB ?Leave a comment:
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Re: Panasonic TH-55AS670A no picture no sound
just tried but did not change anything. still the same symptoms
i'm not getting the 13 blink code anymore, either way (with or with unplugged BL_SOS pin), it just shuts down after a few mins as it seems to be not getting any input and the red led is on solid (not blinking)...Leave a comment:
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Re: Panasonic TH-55AS670A no picture no sound
good idea, i was actually thinking of doing something like that just to see if the backlights would come up for example. in this case should they come up or is it to test the mainboard to see if it succeeds booting up?...Leave a comment:
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Re: Panasonic TH-55AS670A no picture no sound
Sorry I think I know what you meant by now.
I've measured the following voltages on the connector of the mainboard (A Board):
Pin 1: 15.7V (16V)
Pin 2: 15.7V (16V)
Pin 3: 15.7V (16V)
Pin 4: 0 (GND)
Pin 5: 0 (GND)
Pin 6: 0 (GND)
Pin 7: 5.2V (5VS)
Pin 8: 0 (BL_ECO)
Pin 9: 3.3V (SUB_ON)
Pin 10: 3.3V (KEY)
Pin 11: 0 (BL_ON)
Pin 12: 3.3V (POWER_ON)
Pin 13: 0 (PWMA)
Pin 14: 3.3V (BL_SOS)
Pin 15: 0 (PWMB)...Leave a comment:
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Re: Panasonic TH-55AS670A no picture no sound
ok i think this will be out of my capabilities i'm afraid.
if i understand that correct, the software is unable to boot because of this ?Leave a comment:
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