The pin 10/3.3vdc is a output voltage from the power supply and may not drop, even with booting.

If it does, then several parts as the tuners will fail.
This could causes by two sides,
Psu, 3.3v regulator can't bare the amps consumption.
Motherboard, mainly tuners, and one of the tuners consumes more amps than normal.

See if it makes a difference if you not use the external tuners, or one of them.

However, I think it's a psu issue.
_________________________
Doing nothing leads to nothing.

------------- Please note, for technical support -------------
Will be given here, or on the jb8a8f8 forum and I prefer it in English.
Johnny B.

Click on the banner if you like to go there..