Hi @dgluck ,
Normally with Samsung TVs that have a separate tcon board, (I don’t know about monitors) there is a board mounted smd type fuse very close to the cable connector for the cable that comes from the mainboard, check if there is also power on it when the monitor is turned on.
If there is power, then tcon boards do not cause on/off cycling problems. That is usually a mainboard problem (corrupted firmware perhaps?) or a power board problem. The tcon board is used to connect the video signals sent by the mainboard, to the screen and if it is faulty then there is no display or a weird display etc rather than a cycling problem, but again this is with TVs so maybe monitors are different.
Here’s a link to the service manual that may help as it may have the schematic. Usually service manuals do.
Unfortunately, you have to purchase it but at least it is available.
What is the board called in the second picture?
Heae Heae さんによる