PC Bootloop - No Display/Beeps

[Rahul Fernandes]

When I switch on my PC, the fans and lights come on for a second, spin, and then go off. After a couple of seconds pause, this repeats again, and keeps repeating till I disconnect the power. It was working fine till around a month ago, initially, it would display the Motherboard screen and then go off.

I breadboarded the setup and stripped it down to just PSU, Mobo and CPU+HSF without any change. Also switched the PSU and RAM with a known working set borrowed from a friend, so I presume the problem is with the Motherboard or Processor since I don't hear any beeps from the system speaker.

I'd like to know if there's any way I can check which of those two the problem is with, and what a solution would be, since I unfortunately haven't been able to find LGA 1156 components that I can swap in and try anywhere.

My rig (homebuilt way back in 2010)
1) Intel Core i5-750
2) Gigabyte GA-P55-US3L
3) MSI R5770 Hawk (ATI Radeon HD5770)
3) Corsair VX-450 PSU
4) 4GB DDR3 RAM
4) 1 TB Seagate HDD

I've gone through the checklist on this thread without getting anywhere
http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

I've also gone through many other threads with similar problems on this forum, however, I haven't found any solution to this. Please help!

 

[i7Baby]

Disconnect the OS drive, fit an internal speaker and use the post/beep code to help locate the problem. http://www.computerhope.com/beep.htm

 

[Rahul Fernandes]

Thanks, I tried that already with an internal speaker connected, but the PC restarts continuously without any beeps.

Disconnect the OS drive, fit an internal speaker and use the post/beep code to help locate the problem. http://www.computerhope.com/beep.htm

 

[i7Baby]

Boot into Safe Mode (F8) and disable automatic restart on failure.

 

[Rahul Fernandes]

I can't boot into safe mode because the pc shuts down in a couple of seconds without giving me a chance to boot at all

 

[i7Baby]

Then go through Tom's checklist - CAREFULLY - http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems