Question Current build no longer working - blue screens and reboot cycles

Nov 18, 2020
Hi All,

Specs: cpu- i9-9900k Coffee Lake
Mobo: z370 Aorus gaming 7
Gpu: Evga 2070 rtx
Ram: Kingston hyperx predator 4000mhz
Psu: Corsair Rmx 750w

I have built 3 previous PC’s prior to this one so I’m fairly competent at PC building but this one has me stumped.

So I moved house about 3 months ago where my current build was working completely fine. 2 days ago I try to boot my PC and it turns on for about a second and then off in an endless cycle. Tried a PSU tester and the (old) PSU is dead, so I replaced with the one above.

After replacing with the new PSU I have had endless loops of either the PC restarting about 5 times until it will successfully post or if I get into Windows it’s then endless different types of BSOD. At this point I think the duff PSU may have damaged the mobo/RAM. The steps I have tried so far.

1) taken PC back to basics, just one stick of RAM and CPU and then reintroducing components, no difference

2) sometimes the PC will stay stable for a certain period only for it to fall over again

3) CMOS clear

4) different connectors/sockets to rule out further power issues

5) after taking out GPU, 1 stick of RAM and disconnecting second hard drive, I finally managed to format primary SSD after multiple blue screens during the install process, hoping this would stop the BSOD. Managed to get to get fairly stable after that (a few reboots and shutdowns) but now back to constant blue screens when booting into Windows (service handled exceptions) or crashing on BIOS display or multiple restarts with no POST.

6) it won’t let me boot with XMP enabled now.

7) I can get into the BIOS no problem without any crashes.

This build worked perfectly fine up until the move and dead PSU, so before I go and buy another mobo or RAM, is there anything I am missing here? Thanks in advance! (Forgot about memtest86 which I will try tomorrow)

edit: it crashes during memtest86
Last edited:
Nov 18, 2020
If you can again get into Windows take a look at Reliability History and Event Viewer.

Look for errors and warnings that correspond with the Windows BSOD crashes or other problems that may be occurring.
Thanks, I’ll see what’s in there. Just when I think I make progress something else seems to happen, have another mobo on the way just in case