Computer Doesn't Boot

[chix0r]

I have an HP Pavilion p6510f Quad Core Desktop PC. When I turn it on, it appears to power up okay. The blue light turns on, the fans turn on, the hard drives sound like they're spinning, but the orange light that turns on when the computer is "working on something" (sorry, I don't know the technical term for what that light means) doesn't turn on.

Nothing shows up on the screen at all; not the BIOS screen, not anything.

I can turn it off by holding down the power button.

It was doing this periodically for about a week. I cleaned off the fans (didn't help). I tried switching to booting on the backup drive, and that seemed to work; then I switched back to booting on the main drive and that worked for about a week, and now it just won't boot up at all (as previously described).

Does anyone have any suggestions?

[patio]

The light that indicates the PC is doing something is the hard drive activity light...so i suspect your HDD is getting ready to...or already has failed.

[chix0r]

I don't think that's the problem, or at least not the only problem. It won't boot on the backup drive anymore, either.

Also, if one of the drives were dead, shouldn't I still at least see the BIOS?

[Allan]

If you're not seeing ANYTHING on the display the problem is almost certainly one of the following:

1) Bad display (try a different one or try this one on a different system) or

2) Problem with the connection between the display and the system (try different cables if you have them and make sure the connections are tight) or

3) The display adapter needs to be replaced

[chix0r]

I have the computer hooked up to the TV as well, and tried using that as the display screen, but nothing shows up there, either.

I don't think it's a display problem because the orange light isn't coming on. Whenever the computer boots up properly, the orange light always comes on immediately.

Also, when the computer boots up normally, the fan shuts off, but now when I power it on, the fan runs constantly and doesn't turn off until I turn the computer off.

Not sure if this matters or not, but it was previously only not booting after having been turned off all night. This morning I had it hibernating and when I tried to "wake it up" it wouldn't boot. Power light comes on, fans stay on, orange light doesn't go on.

[BC_Programmer]

I don't think it's a display problem because the orange light isn't coming on. Whenever the computer boots up properly, the orange light always comes on immediately.

The Orange light is the HDD light. If it doesn't turn on there is no disk activity. A failed or Failing Graphics Adapter prevents a successful boot- you won't see anything at all and there will be no HDD activity. In this case you would typically get a beep sequence, however- which presumably you are not getting.

Also, when the computer boots up normally, the fan shuts off, but now when I power it on, the fan runs constantly and doesn't turn off until I turn the computer off.

Possibly a failed CPU, power supply, or even Motherboard. Or, in the lucky case, components just need reseated.

Not sure if this matters or not, but it was previously only not booting after having been turned off all night. This morning I had it hibernating and when I tried to "wake it up" it wouldn't boot. Power light comes on, fans stay on, orange light doesn't go on.

This could be leaking capacitors- eg. failed/failing Motherboard. Early failure symptoms as I understand them is that they work best when Warmed, so initially cold boots no longer work, and it takes a few tries to get the system started as a result.

[Lisa_maree]

Hi

This is still quite new is it under a warrantee, if so use that to have it repaired. But it sounds like it has had an extra drive installed which could make a warrantee difficult. Have you tried reseting the cmos here is the details on your motherboard
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01925486&lc=en&cc=us&dlc=en#N543
Refer to the section Clearing the cmos settings.

Do you get any beeps from the motherboard buzzer ?

If not and you are not getting anything on the display suggests the computer is being held in reset
Like the reset button is stuck on. You could test that by disconnecting one of the leads to the reset pins on the motherboard front panel connector or by pressing the reset button a few times to see if the computer starts.
If it does then further investigation is needed.

[chix0r]

I've tried booting with no drives attached, and still no BIOS. It has two sticks of RAM; I tried with each one independently, and no BIOS. I tried replacing the battery in the mobo, but that didn't help.

The jumpers aren't in the default position shown by HP, so I'm not sure I want to mess with them (to my knowledge they've never been moved from when I got the computer).

It doesn't make any beeping noises.

It doesn't have a separate reset button from the power button.

[Lisa_maree]

So is the cmos reset jumper in a different position as if it is it will hold the motherboard in reset

[cengbrecht]

Have you tried with the same type of Ram? (DDR3 most likely) If that fails to post, make sure that you do have a Post speaker on the motherboard, there should be a small round cylinder with  a hole in one end and two wires on the other. If you know where they normally plug in, make sure you have one.

Next things to test, the video card works in another computer.
Your power supply is working correctly.
Your ram is seated fully. (Less likely if you have moved it, but possible)
The ram is good. The onboard video may work if you pull out the video card, test that as well.
If you don't have a video card, test with one.
Try testing with a different power supply.

These are the basics for getting post. This list is not exclusive, but a good start.

One other thing you can try, is to boot the computer with out any ram, and video, that should get you some beeps from the cmos speaker at the least.

[chix0r]

Thank you to everyone who gave advice!

I didn't want to mess with all the possibilities myself, so I took it to a shop. The technician didn't think it was the drives. The power supply tested fine. He put his own power supply in just to check, and it booted fine. He put the original power supply back in, and it booted fine.

I brought it home (with the original power supply in it) and it boots fine! A mystery. So there are a few options:

A. The power supply just needed to be reseated.
B. The power supply is about to go out.
C. The mobo is about to go out.
D. Something's wrong with the processor.

I know HP mobos (at least in laptops) have a history of frying after a couple years, so I wouldn't be surprised if it's the mobo. But for now, it's running again.