Red standby light blinks once, TV won't turn on, Samsung LED TV

"@revelation I am not saying the repair shop is wrong or right, I'd check a few things first. Treat this like you would a ""No Power"" situation.

Use a multimeter and check those points. Let us know what you find."

Can you check pin 4 on connector CN201? It should show 5V. Pin 4 is positive lead and link other lead from the multimeter to ground. Pin 11,12,13 should show 13V.

"Hello,

My Samsung UE40D5000PWXBT, won’t power on , stand by light blink 3 times when pressing power on the remote, someone told me that means the main board is faulty.Is that true?Is there anything else I could check?

If I’m replacing the main board , is it enough to search for it by the tv model , in this case UE40D5000PW ,or does it have to be exact serial number/code as the faulty mother board?"

"I struggle to remember the details back to 2016 when I repaired mine- Is the board you replaced opposite where the power cable plugs in. On my TV, reconnecting (pushing in) the power cable (after disconnecting every time we had a storm) fractured one of the tiny tracks on the board opposite. A dab of solder fixed it.

Regards

Brian F"