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Old 04-28-2018, 11:32 AM
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slipstream55 slipstream55 is offline
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Join Date: Dec 2007
Location: Gilbert, Arizona
Posts: 3
Samsung UN55B8500XFXZA Shuts off by itself w/ clicking

Hello, everyone.


My first time on the this Forum but a regular on the AudioKarma forum. I posted this on the AVS forum but no responses yet.


I have a Samsung UN55B8500XFXZA that has the same problem that everyone else seems to have had with this model (and others) ...the panel shuts off by itself during a program and won't turn on/off with the remote. It has to be unplugged from the wall and after a short period of time the blue power LED turns off. Plug the panel back in again and after a setup scan it works for a while. We're past the unplug and wait before turning back on again stage now to get it to work as it won't power on at all other than a brief wink of the blue power on LED.


I have the back cover off and have done a visual inspection of all of the caps on the Power Supply board. No apparent cold solder joints and no bulging/leaking caps. I do get the clicking relay (about 2-3 second interval) when I power the panel ON and continues to click after power is removed about 15 seconds or so before stopping. When I dis-connect the Main Board and apply power, there is no relay clicking. All other connections remain connected to the Power Supply board. This is/was an intermittent issue. After disconnecting all of the connectors on the power supply board and reconnecting them, I powered the panel up and it worked fine until I shut it off. Just the initial power on relay click.


With power off, I'm getting 0.00VDC across all of the yellow caps except for one that is retaining residual voltage of about 10 VDC and verrrry slowly bleads off.

The fix for this problem (99% of the time) has been to replace caps on the Power Supply board. Problem is, nobody has indicated which ones to replace.

My questions:


I have an ESR tester. Can the caps be checked in circuit?
With no visual cue, which caps would I start considering for replacement?


There are 9 small electrolytics spread across the board as well as 5 large black and 11 yellow ones as shown in the attached jpeg.

Any troubleshooting suggestions would be appreciated.


Thanks in advance.
Attached Images
File Type: jpg Board and caps.jpg (110.9 KB, 40 views)
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