Dual DVD Drives , one not reading - Maybe easy question

I bought a Lite-On SOHW-1693S DVD Drive a week or two back. Have had a number of successful burns (and coasters but thats another story). Anyway, I just installed the same Lite-On Drive on my computer in the other Drive slot replacing my CD-Rom. However, now the first drive is no longer reading dvd’s and my computer seems to be ignoring it. The new replaced drive has taken over and now reads and writes with the no problem. I am wondering if it is something simple. I have both set to Cable Select on the back of the drive. Is that right, should one be different. I just dont have a clue and figured there are plenty of more technical people on this site that will now the answer real easy??

Forget it, I am an idiot. The connection came loose when installing the second drive. I thought since I had power that it was connected properly.

ALLWAYS Best to have a DVDRom Drive my friend…Go n by a Lite-On DVDrom Drive…
Burners are very slow @ Reading…
This is what i have done…i bought a “PCI ATA Ultra 133 card” sloted into a Free PCI slot…Put 4 Hard drives on it. My IDE 0 has a Lite-On 166S DVDrom drive as Primary Master, Primary Slave is my Lite-On 48x CDRWriter. On other IDE 1 I have Secondary Master NEC 3540A DVDWriter as Master & a Caddy for Hard Disc as slave, so i can remove it n incert into my other PCs caddy.

Make sure that first Writer is selected as Master on first IDE (seeing as you not got Rom Drive) n Other as Master or Slave on other IDE…Do Not put Both on same IDE…Normalway to do them------
First IDE>>Hard Drive Master>>>>DVDwriter Slave…Second IDE>>Hard Disc Master>>>Writer Slave…If no HD put Rom Drive Master n Writer Slave.

Actually, the 1693s is a great reader. It is a good idea to have (at least) two different drives though. If one can’t read the disc the other might be able to. Enjoy the 1693s though, great drive.