BN44-00499A Capacitor values / Ratings

[jason123]

Hi,
I just picked up this 55" Samsung (UN55EH6001F) and the symptoms are described as "Shuts off on its own and can be restarted by unplugging from wall and waiting a few minutes"

It ran when I got it for a while without a glitch, but I decided to open it up anyway. Looks like the power supply board has had few repairs, and the obvious one is the capacitors around the connector that goes the main board look like they've been replaced. I'm trying to find the original / correct capacitance and voltage ratings for those.

See photos below. CS852, 851, 855, and 853
Thank you

[R_J]

Re: BN44-00499A Capacitor values / Ratings

I don't have a schematic but based on a picture I found,
CS853 = 2200µf/10v
CS855 = 470µf/10v
CS851 = 1000µf/25v
CS852 = 47µf/50v

[jason123]

Re: BN44-00499A Capacitor values / Ratings

Thank you.. this board has the right values with higher voltage ratings.. should be ok!?!?

[jason123]

Re: BN44-00499A Capacitor values / Ratings

So the issue with this TV is that after 5 minutes or so of turning on, it restarts on its own. Chime and all. After that, it works like a charm. I tried to wiggle cables, connectors,... see if there is something loose, but doesn't seem to be. Any thoughts on what it might be?

[R_J]

Re: BN44-00499A Capacitor values / Ratings

My first guess would be an issue with the main board, likely it it uses a large bga chip, that could be the cause of restarting
You could try and monitor the voltages and see if they drop when it restarts, or maybe try unpluging the main board from the power supply, and plug in the tv, this should turn on the power supply and backlights (no video) and see if runs for a longer time.

[jason123]

Re: BN44-00499A Capacitor values / Ratings

Perfect.. I will give that a shot.. Thanks R_J

[jason123]

Re: BN44-00499A Capacitor values / Ratings

Ok, it does shut down with the main board disconnected. Power supply issue.

Only thing I noticed is the large cap voltage goes from 389 V when good and on to 405 V while it's in the reboot cycle. Means anything? I'd love to fix the power board. Any thoughts where to begin?

[jason123]

Re: BN44-00499A Capacitor values / Ratings

Also, the 13 V (12.7V nominal on the connector that goes to the main board) drops to 0V when it's rebooting with the main board disconnected. The A5V stays solid at 5.29V, but B5V drops to 0 during the reboot cycle (maybe this is normal as it goes to 0 naturally when the set is off - Backlight is off)

[neilc6]

Re: BN44-00499A Capacitor values / Ratings

Restarts could be caused by a bad wifi module. Try disconnecting it.

[jason123]

Re: BN44-00499A Capacitor values / Ratings

Thanks... this tv is not a smart Tv- no network access

[jason123]

Re: BN44-00499A Capacitor values / Ratings

Anyone by any chance has or know where I can get the schematic for this power supply board? seems that there is a solder joint or broken trace as when I apply pressure on the board it seems to work fine. I inspected under a microscope and touched up suspect nodes, but I can't seem to pinpoint it. Thanks

[R_J]

Re: BN44-00499A Capacitor values / Ratings

I would start by resoldering any of the transformer rivits/connections, and also all prts mounted to the heatsinks, don't just look at them, resolder them. they usually are the first to fail.
check the voltages to see which ones quit when you press the board IE: is the standby voltage still there? when it quits.

[jason123]

Re: BN44-00499A Capacitor values / Ratings

Yes R_J A5V is solid does not dropout