Unusual power-on behavior of desktop PC

[hankyjo]

hello, i’m observing strange behavior with my desktop PC during power on. as it happens, the place i stay has intermittent power cuts. without any power cuts, the power-on switch on the cabinet works perfectly fine. in case of a power cut, the PC just refuses to start after the power is back on. the only method which seems to work is:

1. switch off the SMPS using the switch on the back
2. remove the main power plug from socket
3. reinsert the main power plug into the socket
4. switch on the SMPS using the switch on the back

i have reproduced this issue by “simulating” a power-cut. but for this, every device connected to the CPU (USB, HDMI etc.) needs to be removed. otherwise the issue does not seem to occur. my PC config is Gigabyte GA-B75M-D3H motherboard with Corsair CX 430W V2 SMPS

what might be root cause of this problem? would there be any way to solve it without buying a new SMPS?

thank you

[phillpower2]

Hello hankyjo,

Its not a new PSU that you need but a UPS with built in surge protection because at some point the PC will not come back on, add to this that every time it happens Windows is not being shut down properly and that likewise will at some point refuse to boot up.

An example of what you need here