How important are the cables?

[rmdl51]

Hello Guys! I was so confused a few days ago after solving two problems with different computers with just a cable issue, do you know any difference on the IDE cables besides the little plastic guide in the middle of the cable? I can't really tell why, but the problems I had is that I can't read any dvd from a dvd-rw unit, so I test the unit in a dif PC and it works, so later on just change the cable and the unit works , it's weird to me because the same cable works good for a regular CD-Rom unit, but this IDE cable besides it was brand new was kind of old, but I can't tell the difference by just looking at it, is there really a big differente between the new IDE cables and the old ones? same happen with a HDD, I took out the jumper from the HDD and it works, put it back and PC freeze, change the cable and works with the jumper back, I'll appreciate any information that you could provide! Thanks!
:wave:

 

[iss]

There are different cables. 40 wire ones for ATA 33 devices and 80 wire ones for ATA 66\100 devices. both though have the little plastic guide in the center. are you sure this wasnt a floppy cable? they look alot like IDE cables but dont have the guide int he middle.

 

[rmdl51]

No! Floppy cables are 34 pins only and some have also the guide in the middle, I heard about the 40 & 80 wires but not sure how to tell the phisical difference. Thanks

 

[Samstoned]

you will see fat set of 40 wires on one and 80 thin wires on another
not sure but there may be a pin blocked or added
its been long time since I looked at these close