Apple //c disk drive issue

[ECarnby]

This is a problem, yes?



My Apple //c stopped reading disks. I opened it up to clean the drive head (which has fixed it in the past) and was greeted with what looks and feels like expanded foam exploding out of an electronic component that I'm sure has a name, but I don't know it.

Is fixing something like that possible or should I just start looking for a replacement disk drive?

 

[Arcady]

The capacitor ruptured. It's a fairly common problem. You would need to desolder the capacitor (the black round thing) and replace it with a good one. Or you can get that circuit board out of another drive and swap it, if you can find one that has some other problem.

 

[dorkbert]

actually that looked like an inductor. the creamy stuff around it looks like hot glue used to keep it in place.

 

[RWallmow]

actually that looked like an inductor. the creamy stuff around it looks like hot glue used to keep it in place.

Second, not a blown component, just glue.

I would put more money on either REALLY dirty heads (need multiple cleanings), or speed is out of calibration, there's a screw-type pot to adjust the drive speed, and there's some utilities out there to help you adjust disk speed, but if its your only disk drive you probably cant boot those utilities. Could try tweaking the screw a bit either way from its current position, they are usually not THAT far off from where they need to be.

 

[david__schmidt]

I would put more money on either REALLY dirty heads (need multiple cleanings), or speed is out of calibration, there's a screw-type pot to adjust the drive speed, and there's some utilities out there to help you adjust disk speed, but if its your only disk drive you probably cant boot those utilities.

Even an out of speed drive would be able to read its own writing, though. So if you transferred a disk like any of the diagnostic or Copy II+ ones via ADTPro, you would likely be able to boot it. But my money is on a still-dirty head. You do need to be gentle with the cleaning operation - if you pry up too hard on the pressure pad, that can bend the head irreparably out of alignment.

 

[RWallmow]

Even an out of speed drive would be able to read its own writing, though. So if you transferred a disk like any of the diagnostic or Copy II+ ones via ADTPro, you would likely be able to boot it...

True, didn't know if OP was aware of or had proper cables for ADTPro transfer, but yes, you could write a new utility boot disk and calibrate drive from that.

 

[ECarnby]

The first thing I did was try cleaning it. The head was a little dirty, but I've seen much worse. I could try cleaning it again.

If it helps, what happens is that it will spin the disk and then, after no more than two seconds, say "Check disk drive". I've tried a half dozen different disks, so I'm sure it must be a drive problem.

Could try tweaking the screw a bit either way from its current position, they are usually not THAT far off from where they need to be.

Are these the screws you're talking about? They're the only ones I see.

True, didn't know if OP was aware of or had proper cables for ADTPro transfer

I'm vaguely aware of them, but I don't have anything like that, no.

 

[magnusfalkirk]

The first thing I did was try cleaning it. The head was a little dirty, but I've seen much worse. I could try cleaning it again.

If it helps, what happens is that it will spin the disk and then, after no more than two seconds, say "Check disk drive". I've tried a half dozen different disks, so I'm sure it must be a drive problem.

Are these the screws you're talking about? They're the only ones I see.

The screw they are talking about is on the underside of the //c. If you turn the computer over, with the keyboard facing you, you'll see four screws on the bottom. To the upper left you'll see a small hole. This is the screw they are talking about, it's the one that controls the speed of the drive.

 

[RWallmow]

The first thing I did was try cleaning it. The head was a little dirty, but I've seen much worse. I could try cleaning it again.

If it helps, what happens is that it will spin the disk and then, after no more than two seconds, say "Check disk drive". I've tried a half dozen different disks, so I'm sure it must be a drive problem.

The //c is programmed to do just that, if it cant find a "bootable" disk within a few seconds (don't recall exact time out) it drops to Check disk drive

Are these the screws you're talking about? They're the only ones I see.
View attachment 11628


I'm vaguely aware of them, but I don't have anything like that, no.

Magnusfalkirk beat me to it, but no the screws in photo are not what you are after, he is right its accessible through the bottom of the //c, without even having to crack the case.

<--- this is the hole on the bottom for the drive adjustment

 

[Drken]

Since you have your IIc apart & the drive out, here's a view of the underside of the IIc drive with the location of the speed adjustment screw circled in red. Hope this helps. Note that the screw is very small and the slightest turn can have a big effect on speed so it will be a test of your motor skills to say the least!

Ken
www.Apple2Online.com

 

[ECarnby]

I re-cleaned the head and played around with the screw. Doing that, I can get it to work maybe 75% of the time, but it's a very temporary fix. After a few hours, it will be back to not working and I have to play around with the screw some more.

 

[RWallmow]

I re-cleaned the head and played around with the screw. Doing that, I can get it to work maybe 75% of the time, but it's a very temporary fix. After a few hours, it will be back to not working and I have to play around with the screw some more.

Well at least you know its not toast. Did you adjust the drive speed with the utility, or just by guess? You could be just floating on the edge of calibration and it drifts just out of calibration as it warms up.

Or you could have failing components and it could be drifting A LOT as it warms up, or the set screw could be wonky. You could try, while marking or remembering the original position, to spin the screw like a full rotation left and back and a full rotation right and back to "free" it up if its got a bad spot in there, when I say a full rotation, I mean until you hit the stop, do not force it past its stop, and be mindful of where your starting position was, keep track of how far you turned it.

Failing all that, I have ONE spare //c floppy drive I could sell you if you are interested (after I fully test it, it's been sitting a while), and you could ship your broken one back to me. Your profile doesn't say what part of the world you are in, so that may not be feasible, but I thought I would toss that out there as an option.

 

[ECarnby]

I'm just adjusting it a little at a time and seeing if it works -- I don't have any sort of disk utility. I think it's fixed now, though.

It was in the basement, which isn't entirely unheated but does get pretty cold. I thought about how it might be drifting as it warmed up, so I moved it out of there, re-adjusted the screw until the disk read, and now it seems to be working fine. It even read the Prince of Persia disk that I thought died years ago.

 

[RWallmow]

I'm just adjusting it a little at a time and seeing if it works -- I don't have any sort of disk utility. I think it's fixed now, though.

It was in the basement, which isn't entirely unheated but does get pretty cold. I thought about how it might be drifting as it warmed up, so I moved it out of there, re-adjusted the screw until the disk read, and now it seems to be working fine. It even read the Prince of Persia disk that I thought died years ago.

Good to hear that it was just calibration and not something more serious.

As was mentioned in the thread earlier I would suggest looking into ADTPro by david__schmidt, with the proper serial cable to your PC/Mac you can recreate pretty much all the disks you want, plus backup any important disks from your //c back to your PC/Mac, it is really a great tool to get disks back and forth.