Samsung 65" UE65F6400AF ramdomly power cycles

[FerociousBC]

Hello all,

Samsung 65" TV that randomly power cycles. It could be a few hours or a few minutes and then I hear a click sound and reboots. I have updated the firmware to the latest. I'm suspecting the power supply might have bad caps (hoping 🙏...). Inspected the PSU board and none of the caps have any bulging, leaking, or unusual noises that I can hear. Any suggestions? Thanks

PSU: L65X1Q_DHS / BN44-00627A
Model: UE65F6400AFXZA
Ver No: MH01

[FerociousBC]

Well I dropped off the power supply board at the TV repair center and later received this email.... Guess It's a new TV. 📺😒 Thanks for the help everyone. 👍

[Diah]

bulging caps not the only sign of bad one.. ESR measurement the correct way, if you are not able to measure ESR, i would suggest you to replace all caps at the Cold Area, they are not expensive.

[lotas]

Check the cable and its connectors that connect the motherboard to the power supply (burnt contacts, poor contact), a common problem in this chassis.

[FerociousBC]

lotas Cable seems to be fine.
Diah I see the COLD area on the lower right. Where does this area extend to?

[nomoresonys]

The thick white line, see it right beside where it says cold, marks the hot and cold side, in your picture, cold is on the right side. There's 12 electrolytic caps on that side. Also inspect the underside of board for any obvious issues. Bad solder joints etc, can just do an image search for bad solder joints for examples.

[Diah]

try use hair dryer to warm up the 2 caps 680uf 25V, then plug it in wall see if it come on straight

[FerociousBC]

nomoresonys Thank you. No burnt marking on other side of board that I can see but did notice this dark spot JP907/JP908 and this thing on the other side.
Diah I heated those 2 caps for about 2min. Plugged TV in and Powered On with no issues.

[nomoresonys]

When you say powered on with no issues, do you mean the tv worked like it should? If so there's your answer, switch out those 2 caps.

[FerociousBC]

So the TV powers On every time but after several minutes or an hour it will randomly power cycle.

[Diah]

So the TV powers On every time but after several minutes or an hour it will randomly power cycle.

we are confused with yours answer and first post, rework all soldering point on PSU

[FerociousBC]

Sorry, I thought I explained this in the 1st post... But thanks for the help. I really appreciate it. I found this service.
https://www.coppelltvrepair.com/p/20...wer-cycing-etc

[FerociousBC]

Well I dropped off the power supply board at the TV repair center and later received this email.... Guess It's a new TV. 📺😒 Thanks for the help everyone. 👍