My Samsung will not turn on, just a solid red light at the power button on panel. I tried pulling plug to reset, nothing. There is no clicking when trying to power on on the tv panel. I opened it up and there are no blown/bulging caps. I am considering replacing the main board. I do not have access to a meter to test the power board. Is replacing the main board a good start?
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Re: Samsung LN40B640R3FXZA Will not turn on
Can you post some pictures of the overall circuit board layout of the set? Main board failure on this set is common, but other faults exist, too.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search. -
Re: Samsung LN40B640R3FXZA Will not turn on
Also the P/N of the power supply board, I.E. BNXX-XXXXX.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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Re: Samsung LN40B640R3FXZA Will not turn on
See pics. Also the P/N for power board is BN44-00264A. The main board is BN41-01149B.Attached FilesComment
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Re: Samsung LN40B640R3FXZA Will not turn on
Without a meter even simple tests on secondary fuses are out.
Even cheapo 5-10$ would do.Please upload pictures using attachment function when ask for help on the repair
http://www.badcaps.net/forum/showthread.php?t=39740Comment
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Re: Samsung LN40B640R3FXZA Will not turn on
OK, the power supply-inverter board has built-in pull up resistors for the PS_ON and the BL_ON, so disconnect the cable between the power supply and the main board, the backlights should come on when you APPLY 120VAC to the TV.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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Re: Samsung LN40B640R3FXZA Will not turn on
Disconnected the main board from the power board and the backlights came on.Comment
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Re: Samsung LN40B640R3FXZA Will not turn on
probably a bad main board -- need DMM to confirm.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: Samsung LN40B640R3FXZA Will not turn on
I will get my hands on a multimeter. Once I get it, where should I test on the board to confirm?Comment
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Re: Samsung LN40B640R3FXZA Will not turn on
I got my hands on a Fluke MM tester. Where should I start on the main board?Comment
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Re: Samsung LN40B640R3FXZA Will not turn on
First, check the power supply output voltages - 13V and ~5.4V - are OK.
To do this, place your probe on the pin corresponding to that voltage with the connector out. (TV powered on - backlight working. Do not touch any part of power board!) Note voltages.
Then, turn power off, plug in main board connector, and check voltages again in a similar manner. (Press probe onto join where sheath and wire meet, it's a few mm in.) Note voltages.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: Samsung LN40B640R3FXZA Will not turn on
My LN46B630N1FUZA has the same main board.
Anyone know what components are at fault?Comment
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Re: Samsung LN40B640R3FXZA Will not turn on
I do believe a shorted T-con could also stop the Tv from switching on, I would hook it all back up again but this time disconnecting the T-con from the main board(it's the board sitting at the bottom), see if it powers up after doing so.Comment
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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... -
When plugged in it will click and cycle the BL on and off, no pic and does not respond to remote. When I disconnect the cable from the PS board to the main board and then plug it in the BL will come on and stay on. There are only two boards in this set, the LVDS cables from the panel driver boards connect directly to the main board. Since the BL comes on and stays on I'm thinking the PS board is ok and the problem is on the main board. Should I order another main board or do I need to do more testing? thanks, Lee -
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.
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I suppose the real question is whether the existing pinouts from ether a 17IPS71 psu are cross compatible with a 17IPS12 psu? If they are then the exchange of the main boards should have no issues providing the screen is compatible with both main boards. Obviously you can change the screen configurations easily enough (providing you have the correct files) for the main board. Why may you ask would I do this? Well a lot of the smart features are no longer working on a Hitachi 48HBT62U main board I wish to give it a new lease of life!
Obviously the same LVDS connector for the screen connection... -
Hi everybody;
The main board (bn94-09121q) on my UE43J5500 is dead. I can't find the exact same board for a reasonable price, but some other part numbers are pretty cheap, they are physically identical, and based on the bn41-0235 board
Can i swap the bn94-09121q by another "letter", like a bn94-09121N, or even from anoter screen size?
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