Question pc not powering up anymore

[fluffy10135]

so a couple weeks ago my pc would not power up if i press the button and i had to unplug the power cord from the back and plug it back in then usually it worked again, today i tried to power it on and its completely dead, no power comes from the motherboard, tried changing cmos - tested with an old pc of mine and the psu works in there it boots the pc up, also that pc has nother issue which i cant resolve, it powers on , but it keeps showing no signal on the monitor. i have no idea how to fix either of this and have a feeling that the motheboard might be dead, as for the other pc i think motherboard or cpu mightve been damaged , the parts in question is fairly old ( pc 1 - the 1 that has the dead motherboard is a old 3rd gen i7 ) (pc 2 - is an old 1st gen i7, im in no position to upgrade either of them and would rather just try to fix 1 of them atleast, ) the power supply is a corsair gs500 any advice i could follow? and any help would be much appreciated

so far what ive tried regarding PC 1 ( pc with motherboard not recieving or outputting power)
- plugged psu into a different pc
-use a different psu
-reset the cmos
- disconnected the power switch and tried to boot it with the "short " method
-unplugged everything else (ram , gfx card ,drives ect)


and with pc 2 ( showing no signal whilst being up and running )
-unplugged the ram get no beep sound
-tried booting with and without gfx card ( gtx750 ti )

• ( tested gfx card and it works fine )
• pc did this a while back aswell where if i moved it it would do this no signal thing and after a while of fiddling it would work again but havent been able to get it on this time

(fiddling i mean disconnect power completely and insert back onto the board / remove ram and insert again that sort off things.
fans everything power on all lights are on the mother board but no display,
tested with several monitors, tested hdmi - vga and dvi , and display ports

 

[rgd1101]

full system spec?

 

[fluffy10135]

full system spec?

PC 1
i7 3770
16 gb ram DDR3
gtx 750ti
1 tb hard drive
corsair gs500 psu
i will have to check what motherboard it is




PC 2
i7 970/950
8 gb of ram / 16 gb as i can use the ram from pc 1 as well DDR3
gtx 750ti ( its a shared card so whichever pc is on is using the 750ti)
same with the psu and harddrive
gs500 corsiar psu
1 tb hard drive
motherboards a msi x52 pro