Dead motherboard? Gigabyte G1 guerrilla

Aivia

I received a used custom watercooled computer today and everything is good but I have ran into a problem with the computer, it keeps power cycling when I turn it on (also I just tested the water loop by itself before turning it on to make sure it wouldn't leak)

So I took the computer apart completely to eliminate any other chance of there being a short circuit etc and have got it down to just the motherboard.

I have removed everything from the board (so no cpu, ram etc) and also have removed all of the heatsinks and cpu retention bracket just to make sure nothing was shorting.

I have tested the psu is came with and another psu so I know the power supplies are working.

The weird part is that, when nothing else is connected to the board (I mean literally nothing, no ram cpu or anything) except the psu 24pin, when you jump the power on connector the motherboard it lights up and psu fan spins. But if you connect the 8pin cpu connecter and press the power button it power cycles again.

I have tried to switch the bios to the backup one several times on this board but the main problem is just that I can't really reset or change settings (or at least know if I changed anything) if the computer just power cycles with no post every few seconds. I have reset the cmos and changed the battery (and like anything else you can think of involving jumping cmos reset connectors and power cycling the psu etc)

Also I have checked the lights that turn on with the board but they don't seem to have any link with a problem, they just light up to show temperatures and power usages etc

I have connected a speaker to the board but it just gives one click when the board starts and one click when it powers off so thats no help really (although it did give me another search term to try and fix the problem - pc power looping, no post with motherboard speaker clicking - already researched all of those threads and still have not gotten any further.

The computer will power cycle with no cpu installed if the 24pin and 8pin cpu connectors are connected
If I disconnect the 8pin cpu it stays lit up and doesn't do anything (lit up as in turned on "working")
Also if I connect the 24pin and 8pin connectors but hold a short between the cmos reset the board will stay lit up but doesn't do anything.

Also just to mention I have a few other socket 1366 cpus that I was trying such as the i7 920 and various xeon chips, they don't make a difference as the problem is pretty much isolated to the board at this point.

I have cleaned the cpu with isopropyl alcohol and cleaned out the cpu socket with compressed air and rinsed with isopropyl alcohol.

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Not really much more I can think of...
I would just throw the board away as broken but I feel that it is showing some sign of life and just want to give it the best chance before doing that.

Johnboy1951

If the BIOS chip is in a socket I would be inclined to see if I could get a replacement, as you appear to have tried everything else.

Aivia

Yeah the board has the chips soldered onto the board, the fact that theres 2 gives me some hope but im not too sure in myself about swapping them out via desoldering.

Also just to add, this board came with an intel xeon x5698 which from what I can see - is literally not supported on any motherboard ever. Maybe this have some custom bios thats after going bad? (yes I have been trying to get the system to post with this cpu just incase that custom bios was a thing)