[comp.sys.cbm] 1571 troubles

PTS102@psuvm.psu.edu (04/26/91)

My 1571's motor seems to be having trouble grabbing the disk- i.e. the
motor spins but the disk doesn't.  I have to turn the handle VERY HARD
to get the motor to grab, and as a result I cracked the handle off
(there's a knob there now).  Also, at the beginning of a read or write,
the LED sputters as though there's no disk in the drive, but 'catches'
within a second or so.  I've tried cleaning the moving parts of the handle
mechanism with limited results.
By the way,
 The drive is in good alignment.
 The new ROM is installed.
 This happens independently of 41/71 1s/2s mode.
I really think this is a mechanical problem.  Please send responses soon
so I can read them by the end of the semester (may 3).

-------------------------------------------------------------------------
Patrick T. Saxton     "Some people ain't no damn good."               
pts102@psuvm.psu.edu                       -John 'Cougar' Mellencamp  
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iachetta@ec.ecn.purdue.edu (Richard N Iachetta) (04/26/91)

In article <91115.174020PTS102@psuvm.psu.edu> PTS102@psuvm.psu.edu writes:
>My 1571's motor seems to be having trouble grabbing the disk- i.e. the
>motor spins but the disk doesn't.  I have to turn the handle VERY HARD
>to get the motor to grab, and as a result I cracked the handle off
>(there's a knob there now).  Also, at the beginning of a read or write,
>the LED sputters as though there's no disk in the drive, but 'catches'
>within a second or so.  I've tried cleaning the moving parts of the handle
>mechanism with limited results.
>By the way,
> The drive is in good alignment.
> The new ROM is installed.
> This happens independently of 41/71 1s/2s mode.
>I really think this is a mechanical problem.  Please send responses soon
>so I can read them by the end of the semester (may 3).
>
I too am having similar problems.  The drive often has trouble when I put
a new disk in the drive.  It gives Drive Not Ready like the disk is not
formatted.  I usually have to correct this by pushing the disk farther
in by hand with the drive door shut.  Then maybe it will like it.  It also
had trouble formatting brand new disks, giving Bad Disk errors or having
read/write errors shortly later (the disks are double sided, single density).
I took it to a local guy to get it aligned (I figured that was probably it)
but he said it was in perfect alignment, and could find nothing wrong.
So, I'm interested in hearing what people have to say about this.  Thanks

Rich
iachetta@ecn.purdue.edu

consp24@bingsuns.cc.binghamton.edu (Gregg William Riedel) (04/26/91)

>formatted.  I usually have to correct this by pushing the disk farther
>in by hand with the drive door shut.  Then maybe it will like it.  It also
>had trouble formatting brand new disks, giving Bad Disk errors or having
>read/write errors shortly later (the disks are double sided, single density).
>I took it to a local guy to get it aligned (I figured that was probably it)
>but he said it was in perfect alignment, and could find nothing wrong.
>So, I'm interested in hearing what people have to say about this.  Thanks

Yes- I too have this trouble.  All along I thought that it was just me who was
giving every disk inserted an extra nudge...  I just ordered the Free Spirit
1541/71 Drive Alignment Kit- I'll let everyone know how well that works.
I'd like to check the drive motor speed accurately (an old C-64 copy program
tells me its 309.25 rpm, but I doubt that it's reliable.)

Does anyone know where the drive speed potentiometer is on the C128D's 
internal 1571 drive?  If not, how about on a regular 1571 (maybe that'll
help...)

Thanks
Gregg W. Riedel
consp24@bingsuns.pod.binghamton.edu

cs4344af@cse.uta.edu (Fuzzy Fox) (04/26/91)

In article <91115.174020PTS102@psuvm.psu.edu> PTS102@psuvm.psu.edu writes:
>My 1571's motor seems to be having trouble grabbing the disk- i.e. the
>motor spins but the disk doesn't.  I have to turn the handle VERY HARD
>to get the motor to grab, and as a result I cracked the handle off
>(there's a knob there now).  Also, at the beginning of a read or write,
>the LED sputters as though there's no disk in the drive, but 'catches'
>within a second or so.  I've tried cleaning the moving parts of the handle
>mechanism with limited results.

All 1571's that I have seen have a small physical quirk.  When a disk is
inserted and the door is closed, the disk does not always seat properly.
I find that all I hae to do is 'tap' the disk after having closed the
door, and a soft 'click' lets me know that it is seated.  This has
gotten to be such a habit that I forget that I'm doing it, and I have
never seen the problem again.  Tapping the disk is just part of putting
the disk in the drive.

I had a friend who had a problem just like yours (except he didn't break
his door lever), and once I taught him to do the 'tap', he never had
trouble again.

-- 
David DeSimone, aka "Fuzzy Fox" on some networks.          /!/!
INET:    an207@cleveland.freenet.edu                      /  ..
Q-Link:  Fuzzy Fox                                        /   --*
Quote:   "Foxes are people too!  And vice versa."         /  ---

gravillr@prism.cs.orst.edu (GRAVILLE RUSSELL JAMES) (04/26/91)

In article <1991Apr26.022406.19243@noose.ecn.purdue.edu> iachetta@ec.ecn.purdue.edu (Richard N Iachetta) writes:
>In article <91115.174020PTS102@psuvm.psu.edu> PTS102@psuvm.psu.edu writes:
>>My 1571's motor seems to be having trouble grabbing the disk- i.e. the
>>motor spins but the disk doesn't.  I have to turn the handle VERY HARD
>>to get the motor to grab, and as a result I cracked the handle off
>>(there's a knob there now).  Also, at the beginning of a read or write,
>>the LED sputters as though there's no disk in the drive, but 'catches'
>>within a second or so.  I've tried cleaning the moving parts of the handle
>>mechanism with limited results.
>>By the way,
>> The drive is in good alignment.
>> The new ROM is installed.
>> This happens independently of 41/71 1s/2s mode.
>>I really think this is a mechanical problem.  Please send responses soon
>>so I can read them by the end of the semester (may 3).
>>
>I too am having similar problems.  The drive often has trouble when I put
>a new disk in the drive.  It gives Drive Not Ready like the disk is not
>formatted.  I usually have to correct this by pushing the disk farther
>in by hand with the drive door shut.  Then maybe it will like it.  It also
>had trouble formatting brand new disks, giving Bad Disk errors or having
>read/write errors shortly later (the disks are double sided, single density).
>I took it to a local guy to get it aligned (I figured that was probably it)
>but he said it was in perfect alignment, and could find nothing wrong.
>So, I'm interested in hearing what people have to say about this.  Thanks
>
I'm having similar problems.  My 71 will usually read but when formating,
scratching, etc., the drive gives errors.  I checked the alingment and
speed and it checked out perfectly.  I'd like to find out whats wrong.

Thanks
Russ
-----------------------------------------------------------------------------
| Russell J. Graville |       Nuclear Engineering       | Oregon State Univ.|
|     gravillr@prism.cs.orst.edu     |     gravillr@typhoon.cs.orst.edu     |
| (Normal Mail)^  | The death rate is still one per person |   ^(NeXT Mail) |
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joystyk@clmqt.marquette.Mi.US (Joystyk) (04/27/91)

In article <1991Apr26.060123.8666@cse.uta.edu> cs4344af@cse.uta.edu (Fuzzy Fox) writes:

>All 1571's that I have seen have a small physical quirk.  When a disk is
>inserted and the door is closed, the disk does not always seat properly.
>I find that all I hae to do is 'tap' the disk after having closed the
>door, and a soft 'click' lets me know that it is seated.  This has
>gotten to be such a habit that I forget that I'm doing it, and I have
>never seen the problem again.  Tapping the disk is just part of putting
>the disk in the drive.

My friend has this problem of tapping the disk once it's in his drive.  

But you say that all 1571's have this problem?  Mine doesn't.  I just throw
in the disk and nothing more.  No problems with mine.  (Sure, and now
everyone will want to inspect mine.)  :)
-- 
joystyk@clmqt.marquette.Mi.US / Luposlipaphobia:  the fear of being pursued
Trebor Sux                   /  by timber wolves around a kitchen table
I love ADL.                 /   while wearing socks on a newly waxed floor

news@ucrmath.ucr.edu (mr. news) (04/28/91)

>In article <1991Apr26.060123.8666@cse.uta.edu> cs4344af@cse.uta.edu (Fuzzy Fox) writes:
>
>>All 1571's that I have seen have a small physical quirk.  When a disk is
>>inserted and the door is closed, the disk does not always seat properly.
>>I find that all I hae to do is 'tap' the disk after having closed the
>>door, and a soft 'click' lets me know that it is seated.  This has
>>gotten to be such a habit that I forget that I'm doing it, and I have
>>never seen the problem again.  Tapping the disk is just part of putting
>>the disk in the drive.
>
I also tap the disk after I place it in the drive.. 
 
After about 4 years of usage, I found that I had to open up the drive and
put a piece of folded paper (small but thick) under the disk holding
mechanism because it began to stop gripping the hub firm enough.
From: bruce@watnxt2.ucr.edu (Ahmon Dancy)
Path: watnxt2!bruce


------------------------------------------------------------------------------
Bruce! (Ahmon Dancy)  Email Address: bruce@watnxt2.ucr.edu	|  mail me!
	Soon to be attending UC Berkeley      			|  EECS major
------------------------------------------------------------------------------

neusoft@vax1.mankato.msus.edu (04/28/91)

In article <91115.174020PTS102@psuvm.psu.edu>, PTS102@psuvm.psu.edu writes:
> My 1571's motor seems to be having trouble grabbing the disk- i.e. the
> motor spins but the disk doesn't.  I have to turn the handle VERY HARD
> to get the motor to grab, and as a result I cracked the handle off
> (there's a knob there now).  Also, at the beginning of a read or write,
> the LED sputters as though there's no disk in the drive, but 'catches'
> within a second or so.  I've tried cleaning the moving parts of the handle
> mechanism with limited results.


Hmmmm, this seems to be a very common problem.  Well, I have had the same
problem with the C128D's internal drive, but never thought much of it.  In
fact, I found it quite easy to fix.  The problem is that unlike the 1541 drive,
the 1571 is double sided (Gee mike, but what does that have to do with
anything?).  Well, instead of a second head in the 1541, the other side of the
disk rides on a small felt head to put presure on the read/write head allowing
it to read the disk.  When you close the door without a disk in the drive, no
problem...the head simply rests against this felt pad.  The 1571, on the other
hand, puts the second head in place of this felt pad.  If you were to close the
drive without a disk in it now, the two head will come incontact with each
other (not a good idea since the heads are very delicate).  Well, the way
Commodore chose to eliminate this problem was to simply not let the heads come
down all the way if a disk is not in the drive.

If you wish, take apart your 1571 and take a peak inside (note:  I am not
responsible for people destroying their drives (or themselves) out of their
own stupidity...so unplug the damn thing, and don't do nothing unless your
sure about yourself!!!).  Towards the back of the drive (on the left if you 
look from the front of the unit) is a small plate attached to the heads.  
Underneath the plate is a small lever.  The lever is spring loaded so that when
no disk is in the drive this lever will be underneath this plate.  Now, try to
close the drive.  The lever will prevent the plate from coming down all the
way, thus keeping the heads appart.  If you put a disk in the drive, the lever
should go all the way back, so that when the drive door is closed, the plate
(and the heads) will now come all the way down.  

Sometimes (or in the case of most people...most of the time), the lever does 
not go back all the way, and catches on the edge of this plate, preventhing 
the heads to close down on the disk.  A light tap on the disk, or pushing the 
disk in again after the drive is closed, clears the lever, letting the heads 
fall onto the disk (hence the click).  Well, I was able to fix my drive by
bending the lever up(?) slightly, letting the plate catch on the pointed part
of the lever, which will push the lever back as the drive door closes.  Be
carfull if you try this however...the first time I tried it, I let the heads
fall from the open position to the closed posision (which made a loud 'slap'),
and ruined both heads.  Luckily, I was still able to exchange the computer, so
it didn't cost me anything  :)

-Mike
neusoft@vax1.mankato.msus.edu

prindle@nadc.nadc.navy.mil (Frank Prindle) (04/29/91)

Some diskettes, especially if they've been sent through the mail without
adequate protection of the diskette edges, are very tight in their shell
and will have trouble when the drive tries to turn them. Also, my 1571 fails
to grab even a loose diskette about 5% of the times I insert one, but just
taking it out and reinserting it usually solves the problem - it's never
been enough of a problem to try to diagnose it. If you drive consistently
has trouble grabbing the hub of many different diskettes, the spring that
loads the top clamp assembly may be broken.
Sincerely,
Frank Prindle
Prindle@NADC.navy.mil