Topic: problems with 1571 drive

[ruthven]

So I took a chance and bought an untested 1571 disk drive...  and it doesn't seem to work.    When I try to read the directory of any disk, it just clicks in rapid succession, then the green light repeatedly flashes.  No directory is displayed, nor can I load anything.  In C64 mode, when trying to LOAD "$", I get "file not found" and the green light flashes away.  I have the dip switches both flipped up (for device #8) and I'm using the same cord to connect to the C128 that used to connect my 1541--these drive cords are the same aren't they?  I also tried plugging that cord into both ports on the disk drive (same results).

So is it toast?  Anything I could possibly do to fix it (if I were to open it up)?  Any help appreciated--thanks!

 

[megabit]

Go to this site and then to articals 32 and 429. They might help you.
Dan...

[megabit]

Sorry, forgot the site, http://www.floodgap.com/retrobits/ckb/ckb.cgi?mode=all

[RobertB]

When I try to read the directory of any disk, it just clicks in rapid succession, then the green light repeatedly flashes.  No directory is displayed, nor can I load anything.  In C64 mode, when trying to LOAD "$", I get "file not found" and the green light flashes away.

     First, try to initialize the drive by giving the command

OPEN 15,8,15,"I0:":CLOSE 15

or with the DOS wedge or similar

@I0:

Sorry, forgot the site, http://www.floodgap.com/retrobits/ckb/ckb.cgi?mode=all

     Ah, very useful.
     Another possibility is that the 1571 has the old DOS ROM.  If so, the old ROM will have a hard time figuring out 1541 single-sided mode and 1571 double-sided mode.  It will become confused and give confused/corrupted directories.  To correct the problem, you'd have to put in a newer, upgrade ROM or JiffyDOS.

          No more students until August!
          Robert Bernardo
          Fresno Commodore User Group
          http://videocam.net.au/fcug
          July 28-29 Commodore Vegas Expo v8 -
          http://www.portcommodore.com/commvex

[ruthven]

Thanks guys.

OPEN 15,8,15,"I0:":CLOSE 15

Tried that command in both C128/C64 mode--the drive makes those quick clicking noises and then just flashes green continuously (like before).  I am still unable to read the directory or access any files.  Also I noticed that I can't hear the disk spinning inside the drive (as compared to my 1541 drive)--I only hear the initial click sounds.  I wonder if the mechanism is misaligned or broken.  Especially after reading article 429 about how it can be damaged easily in transit.  Another weird thing I noticed is that the drive attempts to spin up (or makes some kind of noise) when I insert a disk even just part way into the drive--also it makes this noise when I remove the disk from the drive (which seemed especially odd)--is this normal for a 1571 drive??

Seems in any case I'm going to have to open this thing up, which I am not looking forward to. 

 

Another possibility is that the 1571 has the old DOS ROM.  If so, the old ROM will have a hard time figuring out 1541 single-sided mode and 1571 double-sided mode.  It will become confused and give confused/corrupted directories.  To correct the problem, you'd have to put in a newer, upgrade ROM or JiffyDOS.

What was the old DOS ROM used for?--was this so that the 1571 could be used on older CBM machines or even old PC MS-DOS machines?  Just seems strange to me that the drive would have a ROM that was incompatible with it's native system/disks...

[RobertB]

Just seems strange to me that the drive would have a ROM that was incompatible with it's native system/disks...

     Well, incompatible might not be the word.  However, it was buggy.  For all the improvements made to it with the release of the newer, upgrade ROM, read CBM engineer Fred Bowen's notes at

     http://www.megalextoria.com/usenet/comp.sys.cbm/1986/000067.html

And JiffyDOS is supposed to correct two or three errors not caught in the upgrade ROM.

          No more students until August,
          Robert Bernardo
          Fresno Commodore User Group
          http://videocam.net.au/fcug
          July 28-29 Commodore Vegas Expo v8 -
          http://www.portcommodore.com/commvex

[Hydrophilic]

Whenever you insert or remove a disk, the disk will break a light-beam.  This is mainly used to test the write-protect tab, but it also serves to spin-up the drive motor.  This helps the disk seat properly when you close the drive door.
 
If you do not hear the disk spinning, the drive motor is not working, or perhaps the drive belt is broken.
 
If it makes clicking sounds trying to read directory, the drive head may be jammed.  The 1571 doesn't normally make a lot of noise, unless the drive head is rammed into track 40 (near the center of the disk).  Another light sensor (near the outer edge of the disk) detects track 1, which is why you do not normally hear the head-banging of the 1541 (the sensor detects track 1 and stops the head to avoid banging)... but there is no track 40 sensor!
 
Good luck!

[ruthven]

Thanks.  I'm going to stray off topic just slightly here while we're on the subject of faulty drives.  I have a 1541 drive that died on me 2 summers ago when I brought it to camp (actually, this 1571 drive I just got was going to be it's long awaited replacement).  The 1541 just died on me in the middle of playing some game--I reset the computer but was no longer able to get it to even display the directory of any disk and it made a similar kind of "head banging" noise.  I've read that 1541 drives are notorius for going out of alignment, mainly due to no track zero detection.  Apparently there was some "homebrew" remedy including software with some sort of calibration disk.  I found the following in a wikipedia article:

There were at least one or two "home remedy" software products on the market during the heyday of the 1541 drive and Commodore 64 computer that could be used to re-align the drive yourself and save a costly trip to a repair center and down time. They generally consisted of a software program and a calibration disk. What the user would do is remove the drive from its case and then loosen the screws holding the stepper motor that moved the head. Then with the calibration disk in the drive gently turn the stepper motor back and forth until the program showed a good alignment. The screws were then tightened and the drive put back into its case. The real problem actually was that the sprocket which moved the head would slip on the stepper motor shaft after repeated hammering and this would put the drive gradually out of alignment.

Does anybody know anything about these "calibration disks"--I'm wondering what they are exactly and where I might get one, or if I could use any 5.25" disk and the software--speaking of which, does anyone know where I could find such software in .D64 format?  I'm hoping this might help me resurrect my old 1541 drive; probably won't help much in the case of my 1571, but I figure I might as well work on both drives now since the tool set is coming out invariably.

[jbni]

Does anybody know anything about these "calibration disks"--I'm wondering what they are exactly and where I might get one, or if I could use any 5.25" disk and the software--speaking of which, does anyone know where I could find such software in .D64 format?  I'm hoping this might help me resurrect my old 1541 drive; probably won't help much in the case of my 1571, but I figure I might as well work on both drives now since the tool set is coming out invariably.

You'll need to buy one. The diskette you use to calibrate the alignment itself has to be properly aligned. If you create an alignment disk with a misaligned drive, all it'll be good for is getting the drive back to the same misaligned point!

I was able to get an alignment disk off ebay not long ago. They don't seem to be very rare.

[RobertB]

I've read that 1541 drives are notorius for going out of alignment, mainly due to no track zero detection.  Apparently there was some "homebrew" remedy including software with some sort of calibration disk.

     As Ray Carlsen says, the best way to align a drive is with the use of an oscilloscope.

          Truly,
          Robert Bernardo
          Fresno Commodore User Group
          http://videocam.net.au/fcug
          July 28-29 Commodore Vegas Expo v8 -
          http://www.portcommodore.com/commvex

[F14DUDE]

Hiya,

Sorry for reopening an old post but I do have a similar problem as the OP.  I got a 1571 drive along with a 128 about a year ago and was working great.  I was able to load up programs and games and without any issue.  And I load it up once a while just to make sure it is working.  As of yesterday, when I boot it up (after a few months), I found the similar issue as the OP where I would get the 'file not found' error and blinking green light.  And yes, I loaded in C64 mode since I don't have any use for the 128 mode and rarely go there nor do I have any 128 disk to boot up with.  I read the two articles 32 and 429 indicated by another user here and also tried to format a disk but no good.  When I tried to format a disk, I entered the command and then computer will say 'Ready' but drive green light would blink.  The moter does spin up and the read head will go up and down the railing twice but then quit.  To be honest, I don't know what could have caused the issue.  The only thing I did to it was unplugged it and plug in an 1541 drive for testing and that was back in July.  I did not take the drive off the shelf (where the drive is hook up to the 128)  nor bang on it at all.

Since I figure it is probably dead, I disassembled the top cover and used a soft cotton tip and a bit of rubbing alcohol and cleaned the two print heads but it still wouldn't work.  All the screws are tight and no cabling issue in any way.  Now after doing that I noticed that the print head would scratch the disk when trying to load the directory or formatting the disk.  Can out of alignment print head cause scratches on a disk itself? 

And the funny thing is, I had an old 1541 which I sold back in July since I didn't need it anymore (which is why I had to unplug the 1571 in order to test the 1541) and now the 1571 itself is bad as well...

Thanks for any info.

[RobertB]

     Upgrade ROM needed?  See my above posts.

          Using a JiffyDOS ROM can also take
          the place of the upgrade ROM,
          Robert Bernardo
          Fresno Commodore User Group
          http://videocam.net.au/fcug

[Hydrophilic]

Was the drive stored with the drive door open?  This is common because you have to have a disk (or dummy shipping cardboard) in the drive before you can close it.
 
If that is the case, you are probably the latest victim of the flawed drive head meachinism.  Specifically, the cheap-ass manufacturer used a flimsly piece of sheet metal instead of a real hinge like on the 1541.  You can check this by removing the top cover, inserting a disk, and closing the drive door.  The top head should rest level.  On the left side (when viewed from the front) is a little arm sticking out which should be just barely (maybe 1 mm) above the rails.  You may noticed it is cocked up in the air several millimeters.
 
Another better way is to look at the base of drive head.  You should see a shiny piece of metal coming from the plastic head and fastened to the main mechanism with small screws.  This metal film should be perfectly flat.  However, it is likely you will find a kink or crease in the metal.  This twists the drive head so it does not sit level. 
 
If the drive head does not set level, the magnetic pick-up coil won't be positioned properly and will have a hard time reading/writing disks.  I guess a bad position might also scratch disks... it is also possible you contaminated the surface while cleaning.  For example a small bit of cotton or paper (whatever you used) may be stuck to the head... or there could have been residue on the head that you clumped into a 'pile'... can't really say for sure about that.
 
My advice would be to try cleaning the disk heads again.  While you're at it check the sheet-metal excuse of a hinge.  If it is creased, you might try using a pair of needle nose plyers to bend it straight.  Of course it is nearly impossible to get it perfectly flat once bent, but with luck you should get it working again. 
 
If you do get it working, it would probably stay working if you never remove the disk, ha ha ha!  But every time you open the door to insert/remove a disk you put stress on that flimsy piece of metal and eventually it will get bent again.  I leave the screws out of both my 1571s so I can easily remove the cover and straigten the metal when the need arises (which is far too often, unfortunately).
 
Oh yeah, be sure to have a blank / dummy disk to test after doing this work.  Try the format command.  Weather it succeeds or fails, you want to check and be sure the head has stopped scratching off the disk coating before using a good disk with valuable data!  If it is still scratching the disk, take it apart agian and clean it again (this scratching of the disk almost surely created a contamination pile on the head).  Try again with a different dummy disk.  That is, never try with a ruined disk.
 
I hope some of this helps!

[F14DUDE]

Hiya,

Thanks for the reply.  I tried to clean the head once more but again.  Unfortunately it didn't help and I'm still getting scratch disk and blinking red lights while "I0" a disk.  I also heard a higher than normal pitch from the drive while the motor is spinning but then subsided quickly.  Also, further examining the interior of the drive, I believe the top heads, (when door closed with a disk inside drive) is rest level so I don't think it is the drive issue.

I guess I just going to get one of those uIEC/SD device and forget about trying to find another 1541 or 1571 drive since they don't last.  I wished Commodore had designed the 64/128 with a 3.5" disk drive in mind since they almost last forever.  I have tons of old 3.5" floppy I used on the PCs back in the early 90s and I can still load them today.  Just other day I pulled some of them out and reformatted them for the Amiga 2000 and Apple IIGS so I can transfer some game images back onto 3.5" disks for both machines.

Anyhow, thanks for the info.  Just a shame that the drive can't be fix.  I hate to throw them out too.   

[RobertB]

Just a shame that the drive can't be fix.  I hate to throw them out too.   

     Ray Carlsen can fix your drive.

          As he has done with many of our 1571 drives,
          Robert Bernardo
          Fresno Commodore User Group
          http://videocam.net.au/fcug

[F14DUDE]

     Ray Carlsen can fix your drive.

Thanks for the info.  I guess send him an email to check for price.