cd turns its self off when plugged in??

[dr_jones]

cd rom is in good working order.. works fine in several other machines

its sharing a channel with a zip drive. when both are wired together the cd doesnt switch on when i boot the pc.(ive tried it as the master and slave)

if i unplug the zip drive and run the cdrom as the only device on the channel it works fine.

ive tried using another crom on the ide channel with the zip and they both worked quite happily.

changed the ide cable and swapped molex connectors.

im at a loss.

[MobilePCPhysician]

Try changing the setting on the zip drive.
Bios auto-detects?

[dr_jones]

the bios is autodetecting both of the drives..i tried manual settings aswell.

the mobos fairly old now and doesnt have a 'cdrom' entry to choose as a predefined unit, so cant do that.

tried lowering the udma and pio settings and that didnt make a difference.

zip and cdrom work together ok if plugged to the primary channel.. but the case is so small and cramped i have to plu em in the secondary. harddrives in the primary..