Pc freezing, doesn't let me format, sometimes it doesn't even boot up.

[razak3l]

Ok guys, so my cousin's pc hasn't been working for over 2 months and I'm here so I wanna fix it. The pc doesnt even boot up sometimes, doesnt even show the gigabyte logo of the motherboard, we just open it, monitor is black its like we didnt even open it but the pc is working. It worked once and we tried to format it, we did and then when we restarted it it was frozen again..i think the hdd is faulty but idk..what to do? Specs : mobo : gigabye f2aa55m-ds2 , amd fx 740k? Something like that dont remember cant see, gpu xfx r7700 series, hdd of 1 tb 8gb ram, please help

[Goowpea]

For me it looks like some sort of RAM issue. You can check the HDD by unplugging it and turning the PC on. It should at least boot up into BIOS. If you have two memory sticks you can unplug one and try to turn it on. You can swapping memory slots. Also try different PSU. If that doesn't help it's probably CPU or MOBO. TBH I don't know how to test GPU. You can always try different one, but I think it'll be hard to get. 

[DelusionalSyko]

Even if the HDD is faulty, the mobo should still POST. I would plug the monitor into the onboard graphics, then try what Goowpea suggested with swapping RAM sticks out.

[Goowpea]

Sometimes when HDD is burned it can power problems. My genius friend tried to plug in the HDD while the PC was running and he fried it. The PC wasn't even receiving power after that with that HDD plugged in. You could press the power button milion times and it was sitting there doing nothing. 
Maybe in this case something familiar happened. Some wierd voltage spike and it fried the HDD. It's possible. That's why I think unplugging the HDD is a good idea.