Black screen, no POST codes

Got a friend's computer here--Compaq Presario SR2011WM. Will not boot, no POST codes, black screen, no hard drive sounds. This is what I've done so far:

Replaced the power supply with a known-good unit. No difference.

Replaced the RAM with good RAM. No difference.

Replaced the hard drive with a good unit. No difference.

Removed the modem and attempted boot (to see if it could be shorting out the MoBo). No difference.

Disconnected the CD and attempted boot. No difference.

Disconnected the hard drive to see if it would at least get a screen telling me that there were no boot devices connected. No difference.

Removed RAM to see if I would get POST code. No POST code.

This computer actually booted from the CD-ROM once and I re-installed XP Pro. Install went well, and the computer booted and ran for a while, then died to black screen and hasn't booted, or done anything else, since.

Does this sound like BIOS, MoBo or CPU? All of the above? If so, how do I tell which one is bad? Has an RC410-M MoBo with a Celeron D 3.2GHZ processor. I don't have a known-good Celeron D processor... Can't do anything with the BIOS as I never get to any kind of screen.

Any help appreciated.

Keith

 

Since CPUs rarely fail out-of-the-blue (unless the cooling fan has been dead for some time while the PC was running and thermal protection had been disabled resulting in thermal damage), it is most likely the motherboard. Have you checked the board looking for 'popped' capacitors? If even one capacitor doesn't have a perfectly flat top and is even slightly popped, it can spell the end of the board. I don't think it's the BIOS because PCs with BIOS problems will usually at least boot up to a post screen or a video BIOS screen since the video is usually initialized first. Below is a picture of some perfectly healthy capacitors (the little green towers are the capacitors, not the copper-coily-thingy). I have seen capacitors so blown out that they are actually leaking a light-beige to dark-brown crud; I have also seen them blown from the bottom so the tops were still flat but there's a bunch of crud leaking from the bottom of the capacitor which sometimes forces the outer cylinder upwards.

 

Did you try removing the video card to see if it POSTs?

 

I've got a feeling it's the Mobo itself. I would have replaced everything you did and still no post.

Look around on ebay, mobo's are cheap