Looking at a TV for a friend. Power supply (BN44-00214A) appears to be ok. I can pull the PS_ON pin High and seem to be getting the proper output voltages. My problem appears to be with the main board, BN97-01995D. As soon as I plug the main board into the power supply, the power supply turns on. The main board is supplying ~3.5v to the PS_ON pin. After a few seconds it drops out, power supply turns off, then back on. It continues this cycle until the AC input is removed or the main board is unplugged. I can't find a schematic for the main board ANYWHERE. Anyone have experience troubleshooting one of these mainboards?
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Re: Samsung LN32A450C1DXZA won't power on
Maybe consider the t-con or inverter boards. The main board could be sensing error from one of those boards and shutting it down.
Pictures would probably help get more responses. -
Re: Samsung LN32A450C1DXZA won't power on
Actually just came across this thread
Looks like inverter is a common fault. Check any fuses on it.Comment
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Re: Samsung LN32A450C1DXZA won't power on
Please supply a good focused picture of the back of the main board.
Look for C102, usually needs replacement.Comment
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Re: Samsung LN32A450C1DXZA won't power on
google "budm c102".Comment
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Re: Samsung LN32A450C1DXZA won't power on
This board doesn't appear to have the c102 cap described in the other threads.
The reason I suspect the main board is due to the fact that it is sending the POWER ON signal as soon as it's plugged in, WITHOUT pressing the power switch.Attached FilesComment
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Re: Samsung LN32A450C1DXZA won't power on
BacksideAttached FilesComment
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Re: Samsung LN32A450C1DXZA won't power on
To the topComment
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Re: Samsung LN32A450C1DXZA won't power on
POWER ON after plug in is normal for many tvs. You may be correct abt the main board but it sure won't hurt to test any other known faults before digging into the main. Good luck with it.Comment
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Re: Samsung LN32A450C1DXZA won't power on
I guess we need to know what the PSon / BLon pins do when the TV goes nuts.Comment
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Re: Samsung LN32A450C1DXZA won't power on
Pretty sure it's a main board issue. I can heat up the shielded portion of the main board and everything is normal. It doesn't send the PS_on signal until I push the power button. At which point the tv turns on fine. I am going to try and remove the shield and see what I can figure out. Will report back.Comment
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Re: Samsung LN32A450C1DXZA won't power on
Look inside that shielded portion and check if you see any capacitors. If you do, change them all with quality caps and report back.Comment
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Re: Samsung LN32A450C1DXZA won't power on
Here's what's under the shield. Any thoughts or suggestions? There is a tantalum cap on the bottom of the board similar to the c102. Looking at the data sheet it is a 100uF 6.3v looks like it is on the 2.5v line. Was planning on changing that and going from there.Attached FilesComment
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Re: Samsung LN32A450C1DXZA won't power on
Got a replacement mainboard for $20, and she's alive again. Thanks for all the input and suggestions.Comment
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Re: Samsung LN32A450C1DXZA won't power on
Thanks for the follow-up on the repair, $20 is a great deal.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Hi and thanks in advance for any input you might provide!
I have a Sceptre U550CV-UMRD8POTV83BB 4K LED (this is a dumb tv) that I bought new in August 2021, so It's just completed 3 years.
Main power board model: TP.MS3683.PC821 T-Con board: N4TP546UHDPU2L_BO
Last Sunday I was watching a dvd and fell asleep for about half hour, when I awoke the tv screen was black and couldn't get the dvd menu to show, so I changed the input to antenna and had sound but no picture, turned it off. I then got online and found this great site! ....read many troubleshooting tips and this... -
ONN 100012588
Issue: No Power, Then Rebooting After Main Board Change
Short answer: replace main board and power board
Technical answer: replace main board and Q306 & Q307 on power board.
Long answer:
TV wouldn't turn on. Power switch was fine which means the main board isn't processing the power on signal. Replaced main board. TV turns on now but randomly reboots. Bad main board? EEPROM? Tried to pull main board and got a shock touching the corner of the board. That's weird. C334 (450V 10uf) capacitor is still holding a high charge.... -
Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
Hi everyone,
Im looking for some advice regarding my Samsung UE55MU8000 TV with main board model BN94-11606C. The TV suddenly stopped turning on and now shows no signs of life at all not even the standby light at the bottom.
Initially, I suspected an issue with the PSU, so I took it to a repair center. They tested it and confirmed that the PSU works perfectly, even on other TVs. Based on that, I started investigating the main board.
I disconnected the main board from the PSU, and the backlight turned on, which seems to confirm the main board is the issue.... -
Samsung LN46C630K1F – Intermittent Backlight, BN44-00341B Power Board
Summary for TL-DR readers:
• Backlight is intermittent, may come on with TV boot or not. No flickering, never fails during TV on.
• Have obtained Samsung schematic & service documents - Can upload if helpful.
• Have read ALL applicable threads
• C1818 and CP820 replaced as low hanging fruit
• CN802 data taken for normal and failed BL operation. SUMMARY: Pin 2 - 5vDet = 3.52 @normal, 0.0 @BL fail. Pin 6 - EPWM = 1.631 @normal, 1.058 @BL fail.
• VCC pin (18) of PFC...
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