Three machines, FOUR flagging 5-1/4" floppy drives?!

[legendre]

My how quickly things can change.. Yes, we all know that rust never sleeps, but dang..

Last time the hardwares were out of storage, everything ran smoothly. Depending on which machines we're talking about, that would be a lapse of three or maybe five years since. But as it stands, I've got four dead or seriously flagging floppy drives.

Crap. I don't know how to fix floppy drives, not yet, anyway.

First one I found is the Chinon Enhancer 2000 (C-64 etc, accelerated 1541 compatible). It's just all read / write errors galore. It can't even format a disc. This drive was flawless and FAST when last used, and that was 3 yrs ago. What a kick in the teeth.

The next two are the pair of 1/3 height units in an Epson QX-10. First sign of trouble was when both drives refused to eject their media; the little lock bar that pops up to block the disc slot refused to retract when the locking mechanism was released. Once that was sorted, it was clear that neither of the drives could reliably read and/or write to the last tracks on the media. Impossible to dupe a disc, etc.

Finally, to add insult to injury, the lone internal drive in the C-64 Executive flaked out. It gets a few good reads / writes, but soon enough it all goes to crap. There is also a very odd scraping / clicking noise which sounds to be coming from just behind the front bezel. Foreign object, right, but I can't see anything - have to pull it out.

So what the heck do you know about floppy drives? The SX-64 is the imperative, then the Enhancer 2000.

Gah, what a mess.

EDIT: 24-JAN-14 I think I see what's essentially wrong with the SX-64 drive - the head doesn't move, at all, ever. It's not stuck, it can be manually positioned. When the drive is running, it's very difficult to move it at all, so that means the stepper is holding it tight - but it's just not positioning it.

Is that a controller failure?

Found this..

UF2 M54532P TRANSISTOR ARRAY IC (STEPPER DRIVERS)
SUB: MITSUBISHI ULN2064
No stepper action or head assembly barely moves. Check also UF3.

UF3 7404 LOGIC
No stepper action or head assembly barely moves. Check also UF2.


Maybe it is a logic failure. Wow, that would be odd... =/

 

[legendre]

Now don't you all pile on this at once.. lol.

PS - it seems like the C-64 Exec drive has *maybe* come around. Seems to be working, but time will tell.

 

[paul]

How are you storing your collection? I never have problems with my floppy-equipped machines and they just sit in a cupboard.

Main thing - don't panic!

 

[Unknown_K]

Did the lube freeze or something?

 

[barythrin]

I'm not that familiar with fixing floppy drives (should be but I generally move on to systems that work lol). The sx-64 IIRC is just a 1541 though if that helps. You probably already found the repair guide since you posted possible chips to test.

The qx-10 does sound potentially like a lubrication issue if you find a doc on that. Let us know how things go. It'll be educational for anyone and a good reference for future (potentially your own if it happens again lol).

 

[legendre]

Did the lube freeze or something?

In the case of the QX-10, yes - that was what prevented the locking lever from disengaging on eject. Like I said, it was an hours' study or better, and then about one minue to make the 'fix', once I knew precisely where to drop the solvent/lube to get the old grease thinned and flowing.

As for the SX-64, it's behaving oddly. When I try to access the drive, +sometimes+ the head will begin to move - and if it does, it will read pretty well and load mostly reliably. But sometimes, the head simply doesn't move - it doesn't even seem like it's trying to move, and it's plenty free to slide along the linear bearings. So again, it's like there is an intermittent either in the head positioning logic, or possibly the pass transistor(s) that I a) assume exist to b) control the larger currents needed to drive the head stepper.

Why would the head remain motionless on some accesses, while other times it just seeks away and loads data pretty much fine? It's a weird sort of intermittent.