------------------------Original Message: From: "Zane H. Healy" <healyzh at aracnet.com> Subject: Re: PDP11 adventures At 7:00 PM +0000 12/6/06, Adrian Graham wrote: If it's just something like the heads sticking, it might be possible to revive the drive, at least long enough to get the data off. BTW, while several other people have done this over the years, I didn't have any luck the one time I tried to revive an RD53, so you'll want to ask someone other than me any questions. :^) I've even heard of people running the drives for years after fixing the problem. Zane -----------------Reply:------------------------------------------------------------------- I've run "sticky" Seagates for years; just had to give 'em a little push start every time there was a power failure. Here's another tip regarding RD53's mike ----------------------------------------------------------------------------------------------- (From http://www.cs.cmu.edu/~jmcm/info/rd53fix.txt) [RD53 spins up and down again] This is a common failure mode for RD53s. If you have backups of what's on the drive, then discard that drive and get a new one. If you have critical data on that drive that you need to save, here's a trick that might let you get it running for one last time: 1. Remove the drive from the machine. Disconnect the two data cables and the power cable. If the drive has the plastic "sled" that DEC uses to mount drives, remove that. 2. Remove the two screws that hold the main circuit board on the bottom of the drive. 3. Flip the logic board up, taking care not to damage it or any of the ribbon- like flexible circuits attached to it. 4. Underneath that board is the servo board. On one side of that board is a small flexible circuit that originates in the sealed drive housing and terminates in a plug on the servo board; I believe it's got three pins. Disconnect this plug. 5. With the drive in this partially-disassembled state, re-connect the two data cables and the power cable. Power-up the system. At this point, the drive should spin up and stay up, but will not go 'ready'. If the drive will not stay spun up at this point, then the drive is beyond help and you are out of luck. 6. If the drive is spinning OK then re-connect the ribbon cable to the servo board. The drive should go 'ready'. 7. Bring up your system and back up those data! When replacing the drive, a Micropolis 1325, I suggest replacing it with a better unit. A Micropolis 1335 will work OK -- all you need to do is jumper position R7 on the drive's logic board for DEC controllers to recognize it as an RD53. Better yet, get a Maxtor 2190 which is a DEC RD54. Not only do these drives hold more, they seem to last longer. Good luck, ---Bob. -- Bob Hoffman, N3CVL