Got a HP Vectra VL5 that's not booting correctly...or at all really.

Powering the device on will rev up the drives and fans, but no display comes up, no CMOS beep either (I can get the system to beep out some error codes if the remove the RAM)
Unplugged all cables from inside, except those required to power the device. All PCI cards removed.

Part of me wants to think the CPU is bad (Socket 7 Pentium MMX). Any ideas, or troubleshooting tips?

Small manual link for those interested;
http://www.manualshelf.com/manual/hp/hp-vectr … ser-manual.html
(My unit is NOT the tower)