Prime95 blend and large FFT tests make my desktop drop without a stop error

[maks]

Memtest ran for 17 hours and 7 passes without error.
How would i test psu without tools?
I found my pau is older than my mobo by a few months in 2011 "Antec TPQ-1000 1000W TruePower Quattro ATX & EPS 12V Power Supply, Modular Cables, Four 12V Rails, 80Plus Certified"
Its ran good for ages. Gonna try dimm slot tests tonight.

you'd run it with a different psu and observe if the problem persists