Loose cable tale
Posted: Sun Jan 24, 2021 4:18 am
Around six months ago our DVR died and was rebuilt with a new motherboard and power supply. The last month on two occasions it locked up briefly but on reboot there were no errors or warnings during the boot. Finally yesterday it did it a 3rd time and on that reboot there were all sorts of /dev/sdb errors. On closer inspection there were a ton of CRC errors, and that in turn suggested a loose cable. So this morning I took it apart, and lo and behold, the SATA cable for that disk was angled up something like 15-20 degrees where it plugged into the motherboard. I have been working on computers for a long long time and have never seen an internal connection do that on a 6 month time scale. As near as I can tell the coiled SATA cable had just enough spring in it to apply a tiny amount of force to the end of the cable, and over quite a long time it was enough to tilt the cable out. The disk end was in square. The motherboard end is now zip tied to a bit of the case about 2" up, so hopefully it won't do that again. Yes, I know there are latching SATA cables, but up to now I have never needed one. This machine wasn't seeing a significant amount of vibration or movement - it was just sitting on a shelf for that entire time.
Just to be thorough the long SMART test was run on both disks. They were both healthy, although the problem one now has a UDMA_CRC_Error_Count of 51.
Just to be thorough the long SMART test was run on both disks. They were both healthy, although the problem one now has a UDMA_CRC_Error_Count of 51.