On 02/09/2018 01:40 AM, Chuck Guzis via cctalk wrote: > On 02/08/2018 10:17 PM, Glen Slick via cctalk wrote: >> Any idea if the drive orientation during storage might make any >> difference in the failure rate? Usual PCB side down, PCB side up, >> either side down, either end down? My guess it that it is best to >> store them in the usual PCB side down orientation, but that is just a >> guess. > Mine are stored on their sides, but I wonder if storing them inverted > (PCB down) would be best for ensuring lubrication distribution. > > --Chuck > I've found flat pcb down seems better. Those working are stored that way and those I've found for spares or parts are on their side currently. Most I've found have been fried already.
Most common problem head crash, likely due to handling. Second up are servo issues maybe due to high temps (some were formerly used in PCs with very poor cooling) and the remainder had board level issues. Of the board level problems the motor drive fried, and positioner driver dead. One had a bad microprocessor n the positioner subsystem. The remainder seem to have likely suffered some ESD or power supply hit. Like I said earlier these drives used a lot of power and ran hot, the lonest lasting and still working units were in BA123 which has better cooling. I know from my time at DEC if the drive was in a MicroVAX2000 the drive life was about half and a drive in a ba23 was longer lasting. Also those mounted on edge seemed a bit longer lasting. The differential between the uVAX2J abd the BA123 life was about 2:1 (about 2 years 24/7 against better than 4), At the other extreme I have over a dozen Quantum D540s (RD52 31mb full height) that are really old and getting older and still work without issues. Some of those have sat on the shelf for a decade and work fine when I need one. Allison
