PC won't boot without external hard drive plugged in

1halfazn

Honorable
Sep 3, 2013
5
0
10,510
My PC won't boot at all, not even into the BIOS, unless I have my USB hard drive plugged in. In fact, once it booted up, I was able to install Windows 10 to my SSD and have everything work just fine. I can even restart it without the external hard drive plugged in. But if I power it off, I have to use the USB hard drive to turn it back on again. I only have to stick it in the USB slot for a second for it to work. I'm not even sure if this is a hardware or software issue actually. If I plug in a flash drive with the exact same contents as the USB hard drive (windows media creation tool), it still won't boot up. Not sure what's going on that gives my USB hard drive this special booting power.

This particular PC was booting fine for the previous owner, and the only things I replaced are the PSU and hard drive.

Oh and changing the boot order in the BIOS doesn't do anything. It's not booting from the USB hard drive in the first place.

I don't think the boot sector being on the external hard drive is the problem either. I tried clean installing Windows from my flash drive and it still won't boot without the hard drive plugged in.

I'm aware of this troubleshooting checklist, and tried many of the steps, but I thought my problem was unique enough that someone could point me in the right direction.

For reference, here's the list of parts I'm using:
MSI Z87-GD65 Motherboard
Asus GTX 670 GPU
i5-4670k quad core
EVGA 500 W1 PSU
WD My Passport External Hard Drive

I've been trying to figure this out for a while now, so I appreciate all responses.

SOLVED: It was my power supply. I replaced it with a higher quality and slightly higher voltage one and all of my issues went away.
 

Zaw___

Commendable
Oct 5, 2016
1
0
1,510