Question Graphics card works in 1 pc but not the other

[Jscheepers]

ok, without posting all the specs I will tell you this crazy issue.
I had a pc for gaming. Bought a new one then took the graphics card out of my old pc and put it in my son's pc and put an older graphic card back into my old pc and gave that one to my wife. Everything was working perfectly fine with no issues. I bought a new computer for my wife who had my old pc but now my son wanted her old pc but wants his graphic card that used to be in that pc back into that pc cause its a better card. So I switch out the graphics card but the pc now don't send a signal to the screen.

I take this better card out, put the old one back in and it works.
OK so I didn't break the motherboard or anything else cause the slot works.

I take the better graphics card and put it back into my son's pc and it works.

So this graphic card works ... the motherboard in the pc i want to put it in works ... and all specs should be fine since this graphics card actually used to be inside this pc when it used to be mine.

I am stumped as to why everything is working but this graphic card won't work in this pc even though it used to .

There is no signal at all... can't even get into the bios.

Oh, I also tried putting this graphic card into my new pc but it don't work in there either. ... but graphics card does work in my son's old pc.

Any ideas ??

 

[rgd1101]

same psu?

 

[Jscheepers]

same psu?

Same everything. Nothing changed. Only thing I did was swap graphics cards . Psu is a 750w
Lights on graphics card comes on and both fans are spinning but no signal. When I put old card back in everything works. So its not screen or cables

 

[Jscheepers]

Any idea ? I am stumped

 

[shiriken]

try resetting the cmos on the mobo it doesnt work on

 

[Jscheepers]

try resetting the cmos on the mobo it doesnt work on

I will try that but I can only do it with the old graphics card. With the newer one I can't even get the bios to display.