Samsung LN37A550P3F

[Super360]

Hi everyone i have a samsung tv here and the red power light just continuously turns on and on trying to turn the tv on and the screen remains black but after awhile the backlight will turn on and the tv makes a effort to turn on but there is no samsung logo and the backlight is just on with no boot up logo and no picture, cant access menu, switch sources etc. I took the tv apart to inspect the boards to see no bulging at all not even slightly even checked the backlight inverter no obvious damage anywhere. I heated up the power board very carefully with a heatgun and when i heat the power caps on the power supply board that makes the backlight turn on with no picture and no bootup logo instantly instead of it taking 15 mins to finally turn on the backlight and eventually keep power cycling, so my question to everyone is this a power supply cap issuehttps://www.ebay.com/itm/Repair-Kit-...item4cf49aa524or is this a backlight inverter issue. Thanks for taking the time to read my thread any help would be greatly appreciated i will post pics of anything that people request. -thanks

[nomoresonys]

Re: Samsung LN37A550P3F

Do you have a multimeter for testing the powersupply?

[Super360]

Re: Samsung LN37A550P3F

Yes I do

[nomoresonys]

Re: Samsung LN37A550P3F

Test voltages at connector CNM802, see the legend/map right to the left of it, test with negative lead to ground back of tv chassis is ok, probe top of connector, theres a 1 where number 1 pin is right there, test with tv plugged in then hit tv on, report back with both conditions, second video shows powersupply testing.

[nomoresonys]

Re: Samsung LN37A550P3F

example, pin 1 xxx then pin 1 with tv power button pressed xxx.

[Super360]

Re: Samsung LN37A550P3F

https://imgur.com/a/uMJQKjAplease check imgur for pics of motherboard
also updated on/off voltage and i checked the t-con board no apparent damage and fuse was perfectly fine.

[nomoresonys]

Re: Samsung LN37A550P3F

.

[nomoresonys]

Re: Samsung LN37A550P3F

.

[Super360]

Re: Samsung LN37A550P3F

that is cmn802 that is just the legend for it and also i should let ya know i bought a cap kit https://www.ebay.com/itm/5x-Panasoni...72.m2749.l2649 for the main psu caps also it amazing turned on and it worked till i unplugged it so i suspect its just some bad caps you can continue to ask question and i will still reply and keep you guys updated on what happens.

[nomoresonys]

Re: Samsung LN37A550P3F

Yes, didn't see your results in the red boxes at first.

[nomoresonys]

Re: Samsung LN37A550P3F

Sounds like a solid plan, without a meter that does esr readings, a recap will fix it or at least eliminate the caps as a fault, let us know how it goes.

[Super360]

Re: Samsung LN37A550P3F

I sure will update you guys with how it goes thanks

[neilc6]

Re: Samsung LN37A550P3F

LNS LNT LNxxA and LNxxB model years are known for bad caps. I would replace them all even if not bulged, ezpecially Samwa and Capxon brands. Though not common, caps can fail and look fine. I have come across replaced caps that are the wrong value or non low esr.

[Super360]

Re: Samsung LN37A550P3F

here is the model/serial for anyone interested.

[budm]

Re: Samsung LN37A550P3F

This model is know for having bad C102 that causes boot loop problem.
http://www.shopjimmy.com/samsung-bn9...550p3fxza.htm#

[Super360]

Re: Samsung LN37A550P3F

you know what now im thinking thats whats wrong with it hmm so im thinking i will still replace all the caps and buy that as well. Honestly i think that repair kit is all thats really wrong but it wont hurt to replace all the caps from a tv from 2008. thanks by the way man.

[nomoresonys]

Re: Samsung LN37A550P3F

I would replace C102, then try it, see if that was the problem, just for curiosity, before you replace the caps.

[Super360]

Re: Samsung LN37A550P3F

ok well thanks for all the help guys i will report back in about a week when all these parts come in.

[budm]

Re: Samsung LN37A550P3F

C102: Notes, white bar on the cap is POSITIVE!
https://www.badcaps.net/forum/showth...highlight=c102

[Super360]

Re: Samsung LN37A550P3F

Thanks for that bro im just going to order the repair kit and replace that cap with the one included, the kit also comes with a 2 new ic's. So just in case the ics are blown as well. btw really appreciate the help everyone especially budm he helped me with a stubborn vizio and helped me fix it almost 2 years ago, so shouthout to budm thanks buddy.