s7520n Black screen after "XP Flash" screen on boot.

[GR_Computing]

This XP Media Center 2006 s7520n Slimline pc fails on boot.   The boot goes normally, (allowing safe mode selection, etc) and displays the XP logo.  After a brief display, the screens blacks out with no cursor.  The green "active" light on the monitor stays on.  The system will stay like that overnight with no change. 

The smart drive tests failed, so I planned to replace the drive, but since I had nothing to lose in that situation, I told the PC to do the destructive recovery option.  It seemed to work, but the end result was the same. 

I ran diags from the ultimate boot disk.   No indications of failure. 

I installed the three recovery CDs which came with the system (on a brand new drive).  They seemed to go ok.

  End result the same.   Blank (black) screen with no cursor after displaying XP logo.

I ran PC-Doctor tests (41 tests).  They took about 7 hours to run.  They failed on the old drive, but ran cleanly with the new drive installed. 

The only optional card in the pc was the modem.  I removed that.  I tried booting with VGA selected.  I booted in safe mode and the system hangs after displaying MUP.SYS being loaded.  I understand that MUP is not failing, but that the system does housekeeping after displaying that message. 

I am going to connect a null modem to try using the debugging boot - but before I do that I thought I'd ask if any of you guys have a suggestion. 

The HP site directed me to the HP repair shop, but that is Best Buy's Geek squad and I have zero confidence in them.   

Summary:   New disk - New software - diags run ok - still will not boot. 

. 

[erico]

Try this

reseat the memory modules and reboot. If that works...wonderful..

Then.

Try another monitor.

Next

Do you have a spare half height video card?  You can install it to verify whether or not the onboard graphics has failed.