Problem adding a Dvd-rom

I have a Lite on Shm 165p6s, I just installed aBenq 1650 DVD-Rom (not the burner), after doing so niether worked, if I unplug one the other works, but not when both are plugged in. Any ideas?
T.I.A.

Hi,

probably the jumpers on your drives are not set correctly.
The jumper of the drive on the end connector of the cable must be set to master (MA) position.
The jumper of the drive on the middle connector of the cable must be set to slave (SL) position.

Alternatively the jumpers of [B]both [/B]drives can be set to cable select (CS) position.

For determining the jumper positions please check the documentation that came with your drives. In case you don’t have them:
Liteon SHM-165P6S
Benq DVD-ROM manuals

Also, make sure, you are using an 80wired IDE cable (identify them by the colour of the connectors: there should be a blue, a grey and a black one on the cable) since this is required for proper operation of your Liteon drive.

Michael