Build a PC Possible motherboard failure


I have owned my computer for 3 years for my birthday. However, in May, I began having some issues.

When I would power on the computer, the display would not turn on. After a few restarts, the display began to work again. The display was connected to my Gigabyte GeForce GTX550 TI. I tried the monitor on another computer and it worked fine.

This issue stopped for some time until one month ago. The issue reoccurred and would not correct itself after multiple reboots. I removed the graphics card and plugged the display into the motherboard and it worked fine. I then cleaned my computer, RAM slots and graphics card port. After this, I retried my graphics card and it has been working fine up until this point.

Last night, I unplugged the peripherals (USB keyboard, mouse and headphones) then plugged them back in, turned my computer off and went to bed (I did this because they were generating too much light when I was sleeping).

When I awoke this morning, I turned my computer on but my headphones began crackling and the sound cut out occasionally. I then tried another port and got a Windows message stating that there was a malfunction. I have tried other devices in this port since and they work fine (possible headphones broken - yet to try on another computer). I powered off my computer then back on to find my graphics card no longer worked (same situation as described above). I have ensured the GFX card is plugged in correctly.

Here are my specs:
Motherboard: ASUS P8H61-MLE
CPU: Intel Core i5-2400 @ 3.1GHz
GFX card: Gigabyte GeForce GTX550 TI
OS: Windows 7 Home Premium
RAM: 8 gig

I don't mind if it is the GFX card (I am looking at another one for my birthday) but I don't have the money to buy both a motherboard AND a GFX card.

Please help me :(