No boot with gpu installed

So a few days ago I was playing csgo and I started to lag really heavily, my fps dipped into the single figures. I restarted the game and as it loaded into another match the pc crashed. Then the pc would turn on but I wouldn't get any input signal on my monitor.

I removed everything besides 1 stick of ram and the cpu and put the speaker into my motherboard and it beeped once slowly and 3 times quickly on boot so this was a gpu fault according to google.

I reset the bios and left the gpu out and used the output from the mobo and it worked fine, booted into windows etc. when I placed the gpu back in I get no output on either gpu or motherboard(or any output to usb but still power to usb).

Specs are:
cpu-AMD FX 6100 stock clock
Mobo-Asus m5a78l/m usb3
gpu-xfx radeon 7850 stock clock
psu- ocz zt 650w 80+bronze

I think my gpu might be dead but I'd rather have some opinions on it first. I have another computer with basically the same specs I can test my parts on but I'm not so sure what im looking for.
PS:not sure of this is the right category so apologies if its not

You're probably right, next step I would have taken would be to see if it would boot in another machine. That would rule out any potential issues with the mobo like PCI bus failure. If not, I suppose see if there's any possibility of an RMA.

EDIT: Just as another note, you may try re-seating the CPU.

Do not quote me on this, but I've HEARD that faulty BIOSes can sometimes do that. Maybe if you flashed the BIOS you could bring it back...? (how long have you had that GPU? Because I just googled it and it looks like that board has issues like yours pretty often. (I don't have the post on-hand where the guy fixed it by flashing the BIOS, but I'll post it here if I can find it again.))

This is probably some really dumb advice, (don't ever do that for a non-bricked GPU) but I figure I'd throw it out there since even if it doesn't work, your GPU is bricked anyway, soooo.....hooray for learning?

Also.......

.....This is probably much better advice.

Though if you do end up having to replace it, at least a 7850 equivalent or better shouldn't be too expensive. It looks like even the 280 is down to teh 150-ish range. : /
Anyway, good luck, boss. Hope this was helpful.