Samsung un55b8500 won't turn on constant click

[Hockeyjock]

Hi everyone I am hoping you can help me. My tv a Samsung un55b8500 has been acting up for a while. At first it would turn off on its own and I would hear a constant relay type clicking from the tv. After waiting for a while (tv clicked the whole time) the tv would come back on and start working again. The frequency between this happening has gotten shorter and shorter until finally my tv has started clicking and will not turn back on. Also during this time my tv would sometime switch inputs on its own.

This actually happened to me about 6 months after I bought the tv and it was repaired under warranty. The tech who came out replaced 2 boards. I'm guessing the psu and main board but honestly I don't remember. I wish I paid more attention.

I have visually inspected the psu and main board and don't see any swollen caps or bad solders. I have done both of this things on other devices with success, but without a visual indicator I am lost. I am pretty handy and I am comfortable soldering small components and can be walked through testing things but I don't have a deep understanding for how capacitors, resistors and voltage regulators work. After reading over some similar threads I disconnected the cable going from the psu to the main board and the clicking stopped. I believe that points to the main board. I did a quick search online and the only place I could fine the board was Amazon and they want over $300 for it. Is there a way I can be guided through the diag process. I have a multimeter but only have a basic understanding of it. I usually only use to to test voltage or opens.

Thanks in advance for any help.

[ReeceyBurger123]

Re: Samsung un55b8500 won't turn on constant click

To me seems like Bga solder issue, with the motherboard disconnected from the Psu does the backlight come on when connected to mains and stay on ?

[Hockeyjock]

Re: Samsung un55b8500 won't turn on constant click

Solder issue? That sounds easy enough to fix. I don't mean to sound dumb but what is bga? Can you elaborate further on this fix.

[Hockeyjock]

Re: Samsung un55b8500 won't turn on constant click

Side note when I plugged in the tv this morning it worked for about 5 min. when main board is disconnected there does not seem to be any backlight. It is hard to tell. But my panel is a full array backlighting. Even when it was working I could only see backlighting behind the part of the panel being used to light up the " no signal" that was being displayed on the tv. Is the backlight supposed to be on if the main board is disconnected?

[ReeceyBurger123]

Re: Samsung un55b8500 won't turn on constant click

Please do some research on what Ive said, also the Bl should come on with Mb disconnected with no picture.

[Hockeyjock]

Re: Samsung un55b8500 won't turn on constant click

There is no backlight when main board is disconnected from psu. I did some quick reading on the bga. This issue seems to be similar to what used to happen to old Xbox 360s. Just to clarify the fix seems to be to heat it up so the chip can reseat. Is that what I should do?

[Hockeyjock]

Re: Samsung un55b8500 won't turn on constant click

Or does no backlight mean I have another issue?

[Hockeyjock]

Re: Samsung un55b8500 won't turn on constant click

So after some further reading disconnecting the main board and having no backlight points to the power supply. I have inspected all the caps and see no bulging. I have also inspected all solders and see no cold solders. What is my next step to diagnosing the power supply?

[budm]

Re: Samsung un55b8500 won't turn on constant click

Samsung BN44-00307A
http://www.shopjimmy.com/samsung-bn4...pply-unit.htm#

So what DCV do you have on each pin of the connector CNM802 (double-row 30 pins) and CNM803 (14 pins) when TV is off and when power switch is activated?
There are charts to tell you what all those pins are so YOU MUST LIST THE PIN NAME/NUMBER AND FOLLOW BY THE DCV READING.