Samsung TV turning off and on

[Sam196]

My Samsung Tv powers up but shows no picture apart for the startup logo and then powers down and does this continuously on a loop. 
Before it was doing is but game me a picture that would then fade to a black screen in less than a second but retain sound and then turn off and carry on in that loop. 
I’ve have tried unplugging and holding the power button down for a minute and then replying in but it makes no difference. 
any ideas before I take it to the tip? 

Samsung Model number UE55TU8500U

[JAMES4578]

Hi @Sam196  Loop issues can be caused by outdated software so see if you are able to update, latest software here https://www.samsung.com/levant/support/model/UA55TU8500UXTW/ 

By any chance are you using a Power surge, if you have a green light on the surge part should be ok.  However if so try plugging directly into a socket to rule that out.  Are you getting a standby light at all, if no red light present that does indicate a fault. can check  troubleshooting with various lights here https://www.samsung.com/us/support/troubleshooting/TSG01001086/#tv-s-red-standby-light-is-off   

Another possible fix though is to hold the Power Button on the Remote for 30 seconds till it hopefully Reboots,unplug from mains for 1 minute and try again.  If no joy an idea to see if a flash reset will work:

Under the Samsung logo on the TV you have a small black button about 2-3cm in from the bottom edge. With the tv turned on
1. press the button at the logo for 5-10 seconds
2. Release the button
3. press the Power button on the TV Remote for 5-10 seconds. Tv goes black and then restarts after a while.

otherwise would need a  repair, can contact Samsung support if you think it is worthwhile https://www.samsung.com/uk/support/contact/ 

[Sam196]

Thx for the possible solutions but they haven’t worked unfortunately. 

[PenetratorNL]

This is an issue with the power supply unit in your TV. It is caused by a failed solder joint on one of the transformers. It makes contact when turning on, then the gap gets wider, and starts arcing. This trips the voltage protection and resets your tv, and boots up again when the joint makes contact. You can see it if you take the back cover off  the tv, place it on a table, lights out and press on. You will see a tiny arc on one  (or more) of the transformer legs.

[Sam196]

Thanks for the solution. I’ve now purchased a new tv and the old one has gone for recycling.