Playing Floppies

[Overheat]

Hey guys,

I’m really wanting to get back into Amiga, so I bought an A1200 and a load of floppies disks. The first floppy drive didn’t work at all, but just swapped with another which seems to read disks.

My problem is this, it’ll read some disks, then I’ll try a few others which don’t work, and then I’ll go back to the first ones and they no longer work. I don’t know what I’m doing wrong, or if floppies are just too unreliable now.

I’ve tried cleaning the heads, which initially seemed to work, but now I’m not getting anything.

I don’t want to get a Gotek as I want that original experience I remember as a kid.

EDIT: I left it about an hour and went back and now the original disk is working again - any ideas what could be causing this?

EDIT2: Gone again, perhaps all these disks are just corrupt - I don’t know!

[Nobby_UK]

Any Capacitors on the drive ?

[Overheat]

Not sure - it’s a Panasonic JU-253-043P - though I wouldn’t know the first thing about replacing caps

[lesta_smsc]

Sometimes the disks may have mould. Your disk head picking up on this and over time it is accumulated which causes it to have problems reading. Just a thought if you clean the head and try same disks is it any better? Also try reviewing magnetic strip as it could have populated with mould. Give these gentle wipe and see if any progress.

Have you got xcopy? I used that for reading disks as it was handy in picking up read errors - not probably what others would use lol.

[Avrovulcan]

Personally IMHO I wouldn't worry about the capacitors. Most if not all are going to be non electrolytic and of the ceramic type. And even then, most if not all the capacitors will be SMD type. Unless you can obtain a circuit schematic of the correct revision with the values clearly marked it would be a very difficult task to perform as SMD capacitors don't have their values marked on them
First off, unless you have already done it, I would carefully de-lid the the drive and lubricate the moving parts with some lithium grease.
You could also try carefully cleaning the drive heads with some isopropyl alcohol on a cotton bud.

Kind regards
Andy

[Hewitson]

Originally Posted by Avrovulcan

Personally IMHO I wouldn't worry about the capacitors. Most if not all are going to be non electrolytic and of the ceramic type. And even then, most if not all the capacitors will be SMD type.

The electrolytic cap(s) are a well known failure for these drives.

Originally Posted by Avrovulcan

Unless you can obtain a circuit schematic of the correct revision with the values clearly marked it would be a very difficult task to perform as SMD capacitors don't have their values marked on them

This can be an issue. Often the capacitance of a bad cap will still measure OK, it's generally the high resistance of a cap that causes it to be bad.

For this application something like a 4.7uF or 10uF would probably be appropriate. You could try several different ones until you got it working if necessary. Certainly not a job I'd call "very difficult".

[Avrovulcan]

In my post I said replacing SMD ceramic capacitors would be difficult not electrolytics.
But your point is taken. I suspect that very cheap quality electrolytic capacitors were used in manufacturing (aren't they always). Or there is issue with the circuit design in general?? Are the electrolytics on these boards through hole or of the aluminium electrolytic SMD type?? I know these can be really unreliable at times.

Kind regards
Andy

[Hewitson]

Originally Posted by Avrovulcan

In my post I said replacing SMD ceramic capacitors would be difficult not electrolytics.

I was referring to surface mount electrolytics.

[solarmon]

I find these JU-253-043P drives to have a high failure rate - granted they are 30 years old, but these seem to fail more than other drives, in my experience.

See my thread at:

http://eab.abime.net/showthread.php?t=98729

I tried replacing the caps and the hall-effect chip, bust still have two such drives that I cannot get to work.

As well as cleaning the read/write heads, have you re-greased the track motor worm gear and guide/glide rails. Also, the check and clean the disk presence sensor switch.

[Overheat]

Thanks for all the advice guys - unfortunately I’m not very technically minded when it comes to this sort of thing - I cleaned the heads with some lighter fluid as I couldn’t find any isopropyl alcohol in my local store. I also picked up some multipurpose oil, which I can try on the rails and work gear too.

If this doesn’t work, is there anywhere you could recommend I send this drive for servicing? I can send the dead drive too if it helps. I could also get the Amiga recapped too as it’s been in storage since the mid90s

[Daedalus]

I've fixed several drives that have had bad *electrolytic* capacitors in them. Some were Panasonic drives, but I don't know the exact model numbers. Non-electrolytics don't go bad in the same way or with the same inevitability.

It would appear that some drives are sensitive to the capacitor's performance.