Wrong termination on SCSI chain


Oct 11, 2020
Just wasted most of the evening chasing a problem on a SCSI chain (well, a chain of one hard drive, to be precise).

Known working Adaptec 2940 controller, known working Seagate hard drive and brand new 50 pin cable(s). Wired everything together, set jumpers on the hard drive and off we go.... "Termination error".

Pulled the drive out to check in case the jumpers had fallen off or what not, reset everything back together, and still no show. Decided to pull the drive out of the case so I could have a better picture of what was going on and realized it was not spinning, which is typically not a good thing.

Long story short, and after a few more checks and trying the drive in the original computer I realized that the brand new cables were borked. Whomever built them clamped the IDC connector in one end with the wrong orientation so the cables were effectively crossed. Had to cut and file the alignment key in one end of the cable so I could insert it in the controller with the right orientation. Luckily, no damage to either drive or controller, but I feel dumb I wasted so much time on it.

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Reactions: flexion and Elf


Feb 4, 2019
Whew, good thing there wasn't any damage. That's crazy that the cable was crimped backwards, talk about bad quality control...

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