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View Full Version : 5.25" Panasonic JU-475-4AK0 problem/repair?



Half-Saint
March 30th, 2016, 11:54 PM
Hi guys,

I have this Panasonic JU-475-4AK0 floppy drive here that just refuses to cooperate. It's one of the three identical floppy drives that I have and the only one that doesn't work. On one machine I can't even switch to B: without getting a "General failure reading drive B:". So I temporarily installed it in another computer that's already using a JU-475 as A: and it acts the same.

I tried cleaning the heads and that didn't help. One thing I noticed is that when the computer does Floppy Seek on bootup, the drive makes an ugly noise, different to what I'm used to.

I found the service manual online but I haven't got any of the tools mentioned in it. Can you guys think of anything? I'd really like to make it work, if possible :)

Cheers

modem7
March 31st, 2016, 12:05 AM
Are you following the termination rules at [here (http://www.minuszerodegrees.net/diskette/5.25_floppy_drive_termination.jpg)] ?

modem7
March 31st, 2016, 12:10 AM
If you search through these forums, you'll find that a common problem with old 5.25" drives is that the [rails (http://www.minuszerodegrees.net/images3/tandon_tm100_rails.jpg)] that the head carriage slides on need to be cleaned then relubricated. Myself and others have found a silicone based lubricant to be satisfactory. The clean/relube is a worthwhile maintenance activity even if it doesn't rectify the problem.

Half-Saint
March 31st, 2016, 12:20 AM
Are you following the termination rules at [here (http://www.minuszerodegrees.net/diskette/5.25_floppy_drive_termination.jpg)] ?

No, first time I hear about the termination rule in over 25 years :-)

I'll try cleaning the rails and see, if that does anything. Cheers

modem7
March 31st, 2016, 12:34 AM
No, first time I hear about the termination rule in over 25 years :-)
Then you have been lucky.
The thread at [here (http://www.vcfed.org/forum/showthread.php?47535-IBM-PC-5170-1-2MB-floppy-drive-trouble)] is an example of improper termination resulting in "very strange sounds and does not work".

Half-Saint
March 31st, 2016, 01:22 AM
I should thank you for the tip. I cleaned the motor "shaft" as well as the head rail and lubricated it with dry lube for bicycle chains :-) It now works like new!

Cheers!