Bad motherboard or something else? Easy way to tell?

[bluegrass dude]

Anything I can do at home to tell which component is bad? Does it sound like the motherboard? How can I test it?

HP Pavilion p7-1420t PC
Foxconn HP-Joshua-H-JOSHUA-H61-uATX
Intel Core i5-3330 3.0G 6M 77W CPU
6GB DDR3-1600 DIMM (4+2) RAM
Intel HD Graphics (Sandy Bridge)
Window 8.1 64-bit
purchased 12/12

My 12-yr old son reported that computer would not start while I was traveling last week. The computer is shut down every night. Last Wednesday, a black screen with blue HP logo was as far as it would get during startup. I looked at it today. The computer powers up and the hard drive spins for about 1 second with the yellow hard drive light illuminated then fading. The fans continue to run. The wired keyboard does not seem to have power as no key lock lights illuminate. I tried all USB ports. I tried start up with the F2, F8 F12, delete and esc keys pressed independtly and together, anyway, with no effect. I also tried a wireless keyboard in all USB ports with no effect either. The keybords work when attached to a laptop. The HP logo comes up instantly as the computer is powered up but that is the extent of the startup. The monitor is a lenovo so its not the monitor screen. I have an image of the screen if there is a way to post it. I have also pulled and reset the RAM and removed and replaced the BIOS battery. USB ports not hot. This computer has given us no problems other than being Win 8 OS...lol. It has never blue screened. I have Norton 360 which runs every 3 days because of the kids using it while I travel and I run Windows Defender once monthly. There is no recent history of viruses or any application or other downloads or any external/internal component additions recently. All significant software is up to date.

Thank you!

 

[alexoiu]

If the PC is still under warranty, I suggest RMA-ing it.
If not, try removing the HDD and booting from a bootable DVD. See if working.

 

[bluegrass dude]

The computer is not under warrantly. I went through all the steps below with no change...black screen with HP logo, no key lock light on keyboard and no beeps except for removing the RAM. I removed each RAM card and tried them in each slot. All with no change. When I remove both RAM cards, I get an error beep sequence with a yellow flashing light at the power button. All subsequent test were done with the 4GB RAM card installed. The CMOS jumper reset had no effect. I disconnected each peripheral individually and then all of them with no effect. The capacitors all look ok. I disconnected the power to the mother board and tried a different power source from another computer that I have and it gave me the same thing. I don't have another Intel CPU to try. I have a AMD Athlon 64 X2 3800 CPU from another computer but don't think that would be compatible with my system. My rig has an Intel i5 3330 CPU in it. I don't have any thermal paste so not sure I should try if it is compatible. I could always get some paste.

 

[alexoiu]

It might be a motherboard issue. Try testing it at a local shop, if not too expensive.