HELP! PC won't won't boot (weirdest issue ever)

[KareemGT]

As weird as it sounds but my PC started randomly freezing lately so i have to rerun it again to get it working but outta nowhere it won't even boot to BOIS now, i still get the speaker single beep but no display, no lights on keyboard nor mouse, the weird thing sometimes it boots after removing the GPU and connecting it back, sometimes removing the sata cable and connecting it back fixes this, if non of that works i end up removing the CPU and placing it back so the PC will boot, even connecting the GPU to the second PCI-EX slot fixed it once but nothing will work twice! The problem will be always fixed by doing something new! I'm so confused now, half an hour ago the machine freezed and i had to restart it but it won't boot now unless i disconnect one of the two PCI-E cables, i get the beep but no display as there is no much power for the GPU but if i connect the other PCI-E cable i won't get the speaker beep so it's useless both ways, I've fixed a lot of machines myself but this case is unusual, i lost hope actually so any ideas?
(AMD FX-8350 - ASUS M5A97 R2.0 - HD 7870 - 2x 4GB ram - PSU : Antec HCG 620m)

 

[smorizio]

try a known good power supply. sound like there an issue on the power good line of the power supply or mb. on the mb try a new cmos battery. if the battery went weak on some mb you may not get video at post.

 

[KareemGT]

try a known good power supply. sound like there an issue on the power good line of the power supply or mb. on the mb try a new cmos battery. if the battery went weak on some mb you may not get video at post.

i tried a new cmos battery but i didn't solve the issue , but i managed to get it to boot by plugging 4 pin CPU connector instead of 8 pins and i used a different SATA cable for the HDD, at this moment i don't know exactly where is the issue but i'll let the machine run as long as possible and see what i get