Computer won't turn on

[Soonarmar]

I'm literally about to tear my hair out with frustration here
Grimmie says you guys could help me out

My computer won't turn on. I at first thought it was a busted PSU which I later confirmed by running it through a multi-meter -- no voltage passing through the PSU. So I bought a new one, hooked it all up and it still won't turn on.
I'm fearing my motherboard is shot but I have no way of telling. Could anyone offer any advice on this?

[Joose]

How much is it not turning on? That might sound like a daft question, but "nothing happens at all" is very different to "the fans spin up but then it just sits there beeping"

[Soonarmar]

Suppose I should have clarified there! Any other information I need to give, let me know

With regards to it not turning on, I mean it literally won't turn on -- I hit the power button, and nothing happens. Powered at the wall, powered at the PSU, all connectors (for motherboard, cpu, gpu, hdd and power button) are working.
I also tested the lead to the power button and current passes through that no problem so I don't think it's the case

[Dr. kitteny berk]

unplug everything from your mobo, add one thing in at a time.

I'd bet it's the memory.

[Soonarmar]

Did so.
Interesting turn of events -- after pulling out my CMOS chip and yanking everything out of my motherboard, bar memory and cpu, it turned on.
So I started adding things one by one. Hard drives are all fine, but my GPU being in makes the computer unable to turn on (this is an issue owing to the lack of an integrated gpu)
so I tried my old 4870 -- turns on fine. fails to boot.
go to my BIOS, see no available bootable drives. only option is "bootable add-in cards"
Wat do?

[Dr. kitteny berk]

Did you have the bios setup differently before? RAID or something?

[Soonarmar]

no, the problems turned up when i switched from one case to another the other day. identical set up, just a bigger case.

[Dr. kitteny berk]

Also, try giving the GPU some wiggling, I find my computer won't run if the cards aren't seated just so, which annoyingly isn't quite square to the case or the motherboard.

[Soonarmar]

I'm 99% convinced this is a motherboard issue for the following reasons:

4870 works but 6870 doesnt -- however, if I swap between the two, I have to flip the CMOS battery in/out
No matter what drive I plug in (4 HDDs and 1 SSD), it will refuse to recognise any of them as being connected
Switching keyboards over (USB) will not work until a reboot complete w/CMOS flipping is done
No matter what position I shift my 6870 into it will flat out not work

[Dog Pants]

no, the problems turned up when i switched from one case to another the other day. identical set up, just a bigger case.

You sound like you more than know what you're doing, so apologies if this is a lesson in egg-sucking, but have you checked to make sure there are no rogue mounting studs causing a short?

[Soonarmar]

no, the problems turned up when i switched from one case to another the other day. identical set up, just a bigger case.

You sound like you more than know what you're doing, so apologies if this is a lesson in egg-sucking, but have you checked to make sure there are no rogue mounting studs causing a short?

No rogue mounting studs at all, I have four screwed into the case, each being utilized. Not sure if it's a shorting issue given the machine turns on fine, it's just a case (now) of it refusing to recognise any of my drives or work with my 6870

[Dr. kitteny berk]

Flash the bios?

[Soonarmar]

flashed bios.
now says "WARNING MAIN BIOS CHECKSUM ERROR"
after PC rebooted, refused to recognise any hard drives still
recognises usb flash drive though

[Soonarmar]

honestly I think I fucked up and shorted out part (if not all) of my motherboard when I was changing cases
I'm so fucking retarded sometimes
so come Saturday I'll nip up NEP and pick up a new mobo
Cheers for the help anyway folks :-)

[Dog Pants]

Unlucky, a dead mobo is always a bitch. Hopefully everything else is okay though.