1541 machine-gun rattle, ?File Not Found

[robinsonmason]

All,

Got my VIC-20 in the mail today! Looks to be in fine working order, but the 1541 I have had in my closet for a while is not doing so well. It's been a couple of years since I fired it up with my C64, so when it failed to find the files on my new Realms of Quest disk, I tried the C64 and media I know was working fine not long ago.

Sadly it looks like I have a drive alignment issue.

Green LED on power up
Recognizes drive (both C64 and VIC-20)
Allows command to load program or look at directory, regardless of disk media it fails with...
Machine gun rattle from drive
Red flashing access light and drive "gives up"
?File Not Found Error
Ready

Anyone have any ideas? I don't have any special PC to C64 cabling or way to make a diagnostic or alignment floppy. All I have are several game floppies, and the new one I just bought for my VIC-20.

Oh well, at least Kenz sent me the .D64 files with my purchase so I can enjoy until my 1541 woes are over.

And on another positive note my tape drive still loads Temple of Apshai on my C64, so I may get one of those VIC-20 tapes in auction.

[RobertBe]

Sadly it looks like I have a drive alignment issue.

(snip)

Anyone have any ideas?

Have you tried cleaning the heads first?

Truly,
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug
The Other Group of Amigoids
http://www.calweb.com/~rabel1/
Southern California Commodore & Amiga Network
http://www.sccaners.org

[robinsonmason]

Robert - if you think that the likely fix then I will look on e-bay for a 5.25 inch floppy head cleaner with the white cleaning pad in place of magnetic media inside the disk and the fluid drops --- or do yo mean a more involved method of taking her apart?

[ral-clan]

Eslapion in Montreal used to offer a fairly reasonably priced drive alignment service.

[pitcalco]

It might not be so serious.

Open up the device and slide the head toward the centre of the disk just a couple of inches and try again.

If that doesn't help, then the drive alignment problem is more serious.

[robinsonmason]

OK Pitalco, that sounds quite do-able. Will try this weekend. Thanks for the tips guys.

[RobertBe]

...if you think that the likely fix then I will look on e-bay for a 5.25 inch floppy head cleaner with the white cleaning pad in place of magnetic media inside the disk and the fluid drops...

I don't know if it is likely, but that is the first thing you should do.

...or do yo mean a more involved method of taking her apart?

Cleaning the heads with swabs is always more thorough than cleaning with a cleaning disk.

Truly,
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug
The Other Group of Amigoids
http://www.calweb.com/~rabel1/
Southern California Commodore & Amiga Network
http://www.sccaners.org

[robinsonmason]

Is there some good documentation out there with photos that you guys would use, or is it pretty obvious where to clean and what to take apart/align?

I'll try a q-tip dipped in rubbing alcohol then - since I'll be taking it apart anyway per the previous suggestion I might as well clean it!

[RobertBe]

Is there some good documentation out there with photos that you guys would use...

Well, the only pic I can find is one for a 1541-II. Here it is --


Right now in the San Jose area,
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug
The Other Group of Amigoids
http://www.calweb.com/~rabel1/
Southern California Commodore & Amiga Network
http://www.sccaners.org

[robinsonmason]

great! I'll let you guys know the results, thanks much.

[ral-clan]

Yes, the drive in the 1541 is pretty similar to the one shown above.

The magnetic read head is the silver or black metal head on the bottom. The top thing that looks like a head in the picture (on top of the Q-tip) is really a felt pad on an arm that keeps the disk pressed against the bottom read head.

You only need to clean the lower part - although in doing so the top felt pad will absorb some of the alcohol. You might want to wait for any moisture to evaporate from the felt before you insert a disk for testing (15 minutes to a half hour would be safe).

There is a lot of information online about how to align 1541 drives - just do a Google search.

There is also a 1541 maintenance/repair guide published by SAMS which is available for purchase on the internet (Amazon.com / eBay). It is a little more advanced, but one of the neat things is that it shows you how to build a simple device to help test when you've got your drive close to proper alignment (not as good as a real oscilliscope but still very helpful).

There's this article, which is a quick fix and not very accurate, but can help in some situations:

http://www.zimmers.net/anonftp/pub/cbm/ ... 6/p064.jpg

That's from Zimmers. I'm not sure if there's more to the article there:

http://www.zimmers.net/anonftp/pub/cbm/ALLFILES.html

[robinsonmason]

Thanks a lot ral-clan - I did some cursory Google searches but my search phrases were not coming up with good results - good tips and articles!

[robinsonmason]

Darn....opened her up, cleaned her as in the docs / images, tried to "align" the head, and got the same results.

Oh well, it was worth a shot!

[ral-clan]

Can a bad VIA chip in the VIC cause these results? I think there are a pair of 6522s in there.

EDIT: just read up on it....no, if the VIA chips were bad the drive would just hang or not be seen by the computer.

TIP: keep this drive for parts. You might need the good VIA chips from it to restore another drive, etc. etc.

[matsondawson]

Can a bad VIA chip in the VIC do cause these results? I think there are a pair of 6522s in there.

EDIT: just read up on it....no, if the VIA chips were bad the drive would just hang or not be seen by the computer.

TIP: keep this drive for parts. You might need the good VIA chips from it to restore another drive, etc. etc.

You could always try interchanging the vias