Re: Samsung UN39FH5000FXZA LCD TV power on cycling

A locally sourced main board solved the problem, thanks for the help.

Re: Samsung UN39FH5000FXZA LCD TV power on cycling

Update: A close look at the main board under magnification revealed a few questionable solder joints on the regulators, one IC, and the pins of the PS connector. Reflowed them and no change, so I guess without any info on the main board I will just replace it.

I also did voltage checks at the main board connector and all voltages that should be there are present and stable, ruling out a bad cable.

Will update when the board gets here and I install it.

Thanks for the help.
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Re: Samsung UN39FH5000FXZA LCD TV power on cycling

You are correct on the part number, screwed that up in original post.

PS BN44-00666A
MAIN BN94-06778C

Thanks, will update the thread when repaired.

Re: Samsung UN39FH5000FXZA LCD TV power on cycling

OK, have I eliminated a TCON problem by disconnecting it with no change?

Also, do you think it may be repairable? I'll have another close look at it under magnification.

Thanks.

Included pics of the back of the TV and both sides of the main board for future....

Re: Samsung UN39FH5000FXZA LCD TV power on cycling

Yes, 3.5V while backlighting is on for 15seconds then drops briefly to 0V, then next cycle, repeat.

Sorry I didn't upload pictures of the board both sides, and thanks for the help.

Just out of warranty at one year old, this started out intermittently then got progressively worse, now it takes many cycles for it to work if at all before giving up ;-)

Turn the TV on and it makes the Samsung powerup noise, backlighting comes on but nothing on the screen. After about 15 seconds, it will cycle through the powerup again and keep cycling until it eventually comes on. When it is cycling you can't turn it off to stop this, it has to be unplugged. Plugging it back in results in the same cycling until it finally comes on or until you unplug it. Once on, the TV will work...

Re: New Members - please post your introductions here

Hi from Surrey BC, joined to get info on fixing my LCD TV.

Somewhat experienced in electronics for about 50 years.

Thanks for the great forum!

Don