ATX Phenom AMD Phenom Mobo issue

I would like some help from the forum if possible. I am trying to repair a HP P6320Y Tower PC. The onboard video will not post regardless of the following:
>CMOS battery removed 8 hours
>CMOS jumper and password reset
>POST test passes
>CPU fan and external fans functional
>Power supply 300v was under specs at 11.77DC, replaced with brand new power supply Diablotek DA 300 Series.
>Serial ATA to drive and DVD are functional
>USB plugged in to Mobo but is NOT functional on any USB port.
>Original Mobo is: M2N78-LA (part#573-400-01, Serial# A1MM06938)
>Purchased a replacement Mobo (used) on E-Bay M2N78-LA (Part#489363-01 Rev A01, Serial#86MM0V7158).
Regardless of all this the PC will not boot into Windows, no on-board video. I cannot use an external video card because it will not let me into BIOS to disable the on-board video.
These problems exist with the original and replacement Mobo.
Without spending $300 for a new original Mobo are there suggestions on what I should do? Please email me at <snip>. Thanks.

 

Welcome to the forum James

I'm a little confused by your problem,your computer has no video but you say it passes the POST test,how do you know if there's no video? Could you describe the original problem,what was the reason for the motherboard change?

Can you describe in a little more detail what happens when you press the power button,screen,hard drive light/activity.

 

Hi, thanks for your interest. This is a 2009 HP PC. They took it to a tech who charged them $140 to reinstall Windows 7. When they got it back the DVD drive wouldn't work and the video wasn't showing on the monitor. I did all of the tests you see on my first thread for this issue. I tested the power supply and it seems the output was less than 12v DC so I replaced it with a new 300w power supply but that didn't help. I checked all the connections, reset CMOS password, pulled the CMOS battery for 8 hours still no video on the monitor. A friend lent me a new Nvidia video card but of course I couldn't bypass the onboard video because the PC will not boot into anything. The keyboard and mouse will not work and neither does any of the external ports. The fans run perfectly and it seems to pass the POST test but no beeps from the Mobo. I ordered a replacement for the Mobo but when it came I tried to match it to the Mobo in the PC but its a different version of the same Mobo and it doesn't help either. Just frustrating to say the least.

 

Again could you describe what a happens when you press the power button,how do you know it "seems" to pass the post test, does the hard drive activity light begin the blink and the hard drive sound like its loading windows? Or do you just mean there are no beep codes?

Can you post the model of the video card your trying for reference,is it definitely known working?

For testing remove all add in cards,hard drive,cdrom,use one stick of memory in dimm 0 and try to boot,then swap for another or a known working one,this will practically eliminate memory problems.

Make sure the motherboard power connector is connected,if the video card needs a power connector make sure its also connected.

 

I was talking to a tech who has 30 years experience. He thinks that when the PC was reloaded with Windows 7 that whoever did that didn't load the drivers, especially the video driver. I might go to HP website to download a video driver to a CD-rom but not sure Windows will install it. He also thinks this must be the issue because the power supply and Mobo are different and the Mobo probably has good onboard video card

 

I can't help you any further because you can't or won't describe the state of the computer from when it's been turned on.

Good luck

 

I have given up on repairing the PC, just too much time involved in trying to get the video to work. I bought them a new Acer tower AMD then put the old HDD in as a slave. Thanks.:wave

 

No problem