Chosen Solution
Okay so I have a Samsung 55 in model number un55ES7100XZA . The television set was power cycling every couple of minutes now there is no standby and no power to the TV after replacing the power supply still no changes but when I remove the cable from the power supply to the mainboard my back lights come on. I don’t want to continue to throw Parts at it because the main board is extremely hard to find is this a common issue for these TVs
It is unusual for a standby light to be affected by a problem within the set that is not related to the power board. Since removal of the connector to the main board allows the back light to work, suggests that the problem is related to the main board. This is not a common error as far as I know. Was this set involved in a power surge or power outage recently? There is a repair service for the main board that may work for you. See the link below: https://www.ebay.com/itm/Repair-Service-… Dan
@roddykelly “there is no standby “ and if you do not have any standby voltage on your main board, it is the main board that has failed. That is most likely the reason why the main boards are not readily available.
You probaly ether blew a fuse or pugged it in backwords therefor frying the prosseser