HP PC not booting locking on bios with lines on the screen.

I think you are saying you have a power supply problem (which will cause this), but I am not certain what your power supply point is.

Try booting just to BIOS (Hold F1 on boot (check for HP)). Does it boot just to BIOS?
Try booting with a bootable DVD or CD. Does it boot this way?

If no kind of boot at all, then the power supply may  be bad, or the motherboard may be bad.

... Thinkpads_User

To add to thinkpads_user's advice:

A quick and easy solution is to grab another power supply and switch it out and see if it boots normally. If it boots normally, the power supply is you problem child. If it doesn't then its either your motherboard or one of your attached peripherals.

It will not boot to BIOS nor does it try to boot from HD or CD.

So then, per my earlier post, probably a bad motherboard or power supply.

... Thinkpads_User

I took the motherboard out of the case and it works fine. It seems that the motherboard is shorting out to the case. I going to to isolate the motherboard from the case by using non conductive washers and see if that fixes the problem.

>>  I going to to isolate the motherboard from the case by using non conductive washers and see if that fixes the problem.  <<   did you check if all holes correspond to a mounting post?
if YES - there should be no shorts - and no need for washers

Did you finish testing the power supply yet? Have you absolutely confirmed that it's the mobo?

And the motherboard shouldn't be shorting to the case. Unless you have your mounting posts touching something they shouldn't be touching. The motherboard should be in constant contest with the case.

It turn out to be a problem with on the memory modules not making good contact. After I reseated the memory module everything worked fine.

then i don't understand your previous post about the mobo shorting....