Pavilion 9880 Wont boot cold

Unbelievable, a machine that wont boot cold, but will after sitting idle and rebooting. Its a HP Pavilion 9880 with Phoenix Bios. After shutting down for 1/2 hour or more when turned back on the BIOS beeps 1 long, 2 short, 98h. Search for option ROMS. Screen stays black, cant get into CMOS F1. Sometimes screen works, it wont detect the HD (error message appears on screen, get into CMOS and wont detect HD). Power is on all components. Leave it sit running for a while to warm up, (runs pretty hot, too)reboot and it picks up HD and goes straight to XP. Then it runs fine as long as it isnt shut off for more than 1/2 hr or so. Warranty is out. HP is no help.