cdrom not working

Please excuse me if I have the wrong forum.
I have an Emachine 500mhz that is a couple years old. I have added a cdrom burner to it. This machine runs Windows 98.
I just purchased an Emachine 900mhz (with Windows XP) and the case is too small to add anything so I did a dumb thing.
I took out the Celeron chip from the 900 and put it in the place of the 500 Celeron chip in the old box. The machine would power off in seconds after emiting several beeps.
When I replaced the chips to their original location the old 500 machine now takes an extremely long time showing the emachine splash screen before it starts to load windows and more importantly:
The cdrom and cdrom burner are not working. The power light is on constantly to the secondary master and the power light is also on constantly to the primary master (HD).
Can anyone explain how to fix the problem?

Thank you - Jesse Staton

 

There is every indication that the replacement CPU did some damage to the motherboard. The floor now belongs to any of our esteemed members who can be more enlightening on this.