Drive :1 Issue(s)

[clh333]

Recently I set aside the Model III I had been using for experiments because the second (top) drive, designated by the OS as ":1", began to misbehave. In a short period of time it went from reading and writing reliably to not being able to read a disk at all. The drive light would come on, the stepper would flail around and eventually, after a long pause, the OS would print the message "No disk". This for a disk the drive had previously formatted.

Needless to say I tried substituting other disks and cleaning the heads, etc. but as further exploration required "unboxing" I replaced it with an NGA Model 4 and carried on. Yesterday, after a few hours of use, the Model 4 exhibited the same behavior for the first time. After trying the same remedies I shut the machine down, hoping that maybe it was a heat-related issue and intending to let the machine cool. This morning on startup the machine once again does not recognize a formatted disk on drive :1.

Both of these machines were acquired in the past 18 months; both had "issues" that I addressed with the help of the VCF membership. The power supplies were rebuilt, the drives cleaned, the memories expanded to max capacity, the ports' operations verified, video output "tweaked". With each machine I put the "better" drive (more reliable, less frozen or crusty) drive in the :0 slot, so maybe this is just a final chapter in a failing drive's life story. It could be a connection issue somewhere along the data line; or a failing capacitor on the drive or the controller board. It could be the controller itself, although it is hard to imagine the controller operating drive :0 and not :1. Or it could be something I've never thought of.

So I'd like to ask for suggestions as to how to proceed. In the past, where possible, I've substituted a working drive for the problem drive, but it's getting hard to find these old drives and I'm going to have to take a different path.

Thanks for your help.

-CH-

 

[ldkraemer]

What Brand Floppy Drive is giving Trouble? Tandon TM-100-{1, 2A, 4}

If it is a Tandon, I always start by Cleaning the Drive Rails with a Cotton Swab dipped in Alcohol. To do that I remove the
Head cable(s) and swing the Logic board out of the way. That way I can get to the rails easily. After Cleaning the rails I use
another Cotton Swab to GENTLY clean the Drive Head(s), looking for dark brownish oxide deposits. If none are found, I lube
the Guide rails with about 3-4 drops of Dri-Slide. Dri-Slide is a Motorcycle Cable Lubricant, that does not attract dirt, and lasts
for years. Any Motorcycle shop should have Dri-Slide available. A small can will be a lifetime supply when used on Scanner
Rails and Floppy Drives.

I GENTLY move the Head Carriage assembly through a complete full length travel after lubricating, stopping in the center of travel.
While the logic board is off I look at the Door Hinge to see if there are two short White Nylon Pins in the Door assembly. If they
exist the Door hinge part likely has a broken ear. I replace the Broken Hinge part and use a full length piece of Brass Brazing
Rod to replace the two short White Nylon Pins. Just about every Tandon I have that has had the two short White Nylon Pins
has had a Broken Door Hinge part. After that I reassemble the Logic Board and reconnect the head Cable(s) to the Logic Board.

Then I use my Supercard Pro to Set the Drive Speed to 300PRM and exercise the Head carriage assembly. You can use it to
step to any Track and I make sure it is quiet and is moving in both directions. The Supercard Pro can do a Media Test of a
questionable floppy(s).

When that is done I double check my Dip Switch for Drive Select (Supercard Pro uses DS1 in a {0..3} configuration) and install
the Floppy in the computer it was removed from.

Larry