Apple //c Floppy Drive

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Apple //c Floppy Drive

I recently picked up an Apple //c with a monitor. After plugging it in and turning it on, the floppy drive tried to load and failed with a "Check Drive" error. Expected as there was no floppy in the drive. Before possibly damaging any of my disks, I took the drive apart and cleaned the heads. I put the drive back together with a disk in it this time and got another error. Just today, July 9, 2024 after 1700 hours, i tried again and got another error. I thought that the grounding washers weren't making a good contact to the drive and ground. I tested the connection with my multimeter and both corners checked out fine. I checked that the heads could move freely and that checked out. I left the cover of the drive off, inserted a copy of "Computer Inspector" and it finally loaded. I teted the RAM and the ddrive and "Computed Inspector" responded that everything was in good shape. I buttoned the drive back together, and tested it once again. Once again it returned an error. I'm at a loss of what to do now. The dirve seems to work fine and I know the floppy controller circut works fine too as I have dried with an external dirve. Is this some sort of bug with the original ROM or is the solution staring me right in the face and I'm not seeing it.

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On Apple IIc "disk drive errors" ...

... every single Apple IIc I ever had with such errors actually had a bad DRAM, and the disk drive was OK. Most of the bad DRAMs were in the right hand side, lower corner, as if there is a heat pocket there which kills DRAMs due to overheating.

 

But it was only about half a dozen of these. So my statistical base is limited. Yet another observation of mine is that about half of them not only had the bad DRAMs in that corner, but also a blown up IWM. My conjecture is that once the bogus "disk error" or "boot error" (don't recall which text it was) comes up, users mess around with the disk drive and blow up / damage the IWM in the process. The sad remains are sold on Ebay and the next owner now has two problems to find and fix, the bad DRAM and the blown up / damaged IWM.

 

But your case may be different, of course.

 

- Uncle Bernie

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Uncle Bernie's on to

Uncle Bernie's on to something important.

 

Before you muck around with your disk drive any further and risk more damage, you should first do a power-on-self-test by powering on while holding both APPLE keys down.

If that passes, then you should verify that your floppy diskette itself is good.  No sense blaming the drive for a problem with the diskette.

 

There may be more than one issue at play, but let's not dive too deeply into the shallow end.

 

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Before you attempt a self

Before you attempt a self test, drop to basic and type PRINT PEEK (64447)<return>. If it replies with 255, don't bother trying. If it's 0, 3, or 4, it's worth a shot.  

 

Also, OP did say that at one point they were able to run a MECC Computer Inspector RAM test, and it did pass. Not to say it didn't miss something. But does make it less likely. 

 

 

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nick3092 wrote:Also, OP did
nick3092 wrote:

Also, OP did say that at one point they were able to run a MECC Computer Inspector RAM test, and it did pass. Not to say it didn't miss something. But does make it less likely. 

If that's the case then the things to check are drive speed and head cleanliness.

 

 

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The //c drive has a metal

The //c drive has a metal perforated cover/cage that fits fairly closely/tightly around the top of the drive. Rereading the original post, it sounds like the drive works when the cage is off. But acts up as soon as the cage is back on. Would need the OP to confirm that is the case. If that is the case, I'd look for something maybe accidentally shorting to the cage. 

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