Well,, failing or bad PSU's can produce some really weird problems.
We had a system that we were certain was an hardware or OS issue.
Everything we did we could not narrow it down.... PSU was adequate and tested fine.
Replaced the PSU for poops and giggles, just cause we had exhausted all other reasons.
No more problems.
Put the failing PSU in another system and whammo,,, problems out the wazzu.
So yes,, trust me,, they can do some really weird things.
I also had a bad PSU that caused wired problems,,, ,, replaced it and no more problems.
In fact, the PSU I have now,, is under powered for my system. I have to becareful of the number of USB devices I hook up.
With that said,, it may not be his problem,,, but booting to a blue black screen could be an indication of an under powered or failing PSU
But could be the following.....
Bad Video Card,
Bad Drivers
Bad Monitor
Bad Cable
Corrupt OS
Video Card not seated properly
Failing/Bad PSU