Samsung ln40a550p3f red blinks then nothing

[mattstolte]

I dont even get the samsung melody, the red led just continues to flash, no pattern. Tv wont turn on. Everything seems to have all voltages, im thinkin main board fault? Im able to get voltages going to inverter, shouldnt i only get that when tv is on? But this aint powering on?

[budm]

Re: Samsung ln40a550p3f red blinks then nothing

Another one of those LNxxA550 series:
Please read post 129, 135, 136 and the links.
You can try adding the cap to the board and see what happen.
https://www.badcaps.net/forum/showth...t=25810&page=7

[mattstolte]

Re: Samsung ln40a550p3f red blinks then nothing

Yes bad main board thanks

[mattstolte]

Re: Samsung ln40a550p3f red blinks then nothing

Bud what cap is that i tried pulling up your pics from ur thread and i cant get them to come up

[budm]

Re: Samsung ln40a550p3f red blinks then nothing

https://www.badcaps.net/forum/showpo...&postcount=129

[mattstolte]

Re: Samsung ln40a550p3f red blinks then nothing

Yeah thats the picture i was talking about, they wont pull up for me, and i didnt understand how to add a cap to the connection?

[jasonbay13]

Re: Samsung ln40a550p3f red blinks then nothing

same problem, blinking red light and tv never turns on. no attempt, no sound, nothing.

i tried the cap in parallel with c102 on the main board and the tv comes on.
my question is: can i simply just leave the cap soldered parallel with the smd? currently just using some low esr electrolytic i had.

edit: might have answered my question... after less than a minute the screen messes up (like interlacing) for a few seconds then goes back to normal? would this be from that?

[dick_barton]

Re: Samsung ln40a550p3f red blinks then nothing

Double check you have the capacitor fitted the correct way round.

[jasonbay13]

Re: Samsung ln40a550p3f red blinks then nothing

the white line on the smd is negative?

[jasonbay13]

Re: Samsung ln40a550p3f red blinks then nothing

so i've replaced both capacitors as suggested. now that the tv turns on, i am getting as shown in the images. its random and can stay good or bad for seconds, or flicker between.

[budm]

Re: Samsung ln40a550p3f red blinks then nothing

White line on that black tantalum smd cap c102 is positive.

[budm]

Re: Samsung ln40a550p3f red blinks then nothing

so i've replaced both capacitors as suggested. now that the tv turns on, i am getting as shown in the images. its random and can stay good or bad for seconds, or flicker between.

That is bad tab bonding problem, try flexing the screen to see what happen.

[jasonbay13]

Re: Samsung ln40a550p3f red blinks then nothing

White line on that black tantalum smd cap c102 is positive.

oh. well, replaced with other smd caps with white line in same direction...

as for the screen, movement doesnt seem to affect it, but i will take a better look and try putting pressure in various spots. thanks for the quick response.

[jasonbay13]

Re: Samsung ln40a550p3f red blinks then nothing

That is bad tab bonding problem, try flexing the screen to see what happen.

i was hoping you were wrong :/

i pulledoff the bezel and lightly twisted the frame and the problem got worse, twisted it the other way and it was fine.

is there a chance to fix this? or should i assemble first and hope that it holds up while screwed together?

[budm]

Re: Samsung ln40a550p3f red blinks then nothing

https://www.badcaps.net/forum/showth...ht=tab+bonding
https://www.badcaps.net/forum/showth...ht=tab+bonding
https://www.badcaps.net/forum/showth...ht=tab+bonding

[jasonbay13]

Re: Samsung ln40a550p3f red blinks then nothing

indeed you are right. it was the far left tabbing. the part that bends down into the lcd. scary stuff, i just stuffed a bit of cut up mousepad in there behind the metal frame to keep pressure on it. hopefully it lasts long enough and doesnt act as a thermal insulator, that'd be bad probably. do they always get so hot?

[budm]

Re: Samsung ln40a550p3f red blinks then nothing

All four of those TV's are still running good.