Stange PS4 Pro behavior (Maybe BLOD)

So first motherboard MVB-003 1-982-713-11. I’ve searched for week now and testing and I have really strange BLOD problem. First PS4 started to shut down randomly, I check if it was clogged everything clean then I changed thermal paste, and it didn't work. Then reinstalled everything on new hard and again same problem. Check if the hdmi port was destroyed nothing, everything was perfect, new cable the same thing. And now the it doesn't won't start, Its just blue light blinking can't get into safe mode or anything. If I leave it for a couple of days it starts normally and after some time just crashes and back screen and blue blinking light.

List of stuff I tested:

Power supply perfect condition nothing burnt, normal voltages.

HDD

Thermal paste.

Motherboard again, nothing burnt, but they are some weird spots that look like water marks, but only on one or two exposed copper traces.

And tried leaving blue-ray unplugged.

So does anyone have any idea or is that just a clear sign that it needs to be reballed.