So, I found the source of the problem.
Tested with my GSkill RAM 2133MHz base (i thinkg), 2800MHZ in XMP.
The Ryzen sustem work fine as long as i dont use the 2800MHz speed.
I geuss the R3 3100 doesn't support high speed RAM.
when i put back the corsair 3200 MHz RAM nothing, so to me this confurme its a speed problem.
Also, the PSU on my brother PC was bad, something is not working in it (I geuss the 5v or somthing) because the fans turn but no boot. with my PSU the PC work fine.
In summary, R3 3100 + fast RAM = no good ------ R3 3100 + Slow RAM = good -------- PSU = BAD somehow.
thanks all for your help especialy Filingo.