Re: Adding a second floppy drive to an Apple IIe

["Bill Garber" <willy46pa@comcast.net>]

"Michael J. Mahon" <mjmahon@aol.com> wrote in message u9mdnU2KU-U5xV_QnZ2dnUVZ5rmdnZ2d@giganews.com">news:u9mdnU2KU-U5xV_QnZ2dnUVZ5rmdnZ2d@giganews.com...
> Jeff Shanholtz wrote:
>> Well, I'm having second thoughts and may want to revive one of these
>> after all. 2 of the drives are off brand and 1 is apple so I'm hoping
>> to get the apple one working. It does spin up at boot time and I hear
>> the familiar booting sound coming from the drive, but at that point it
>> just spins without any hint of real activity (with a bootable disk in,
>> of course). Are there any troubleshooting guides available somewhere
>> to help me fix this? I do have hardware repair experience but I
>> wouldn't know where to start looking, and I'm guessing someone has
>> compiled a document somewhere about restoring these things.
>>
>> These symptoms don't strike me as being explained by one of the
>> mechanical problems described by you, Michael, but if you disagree I
>> would be happy to crack her open and have a look.
>>
>> I appreciate the advice!
>
> Dave is right, a blown 74LS125 will disable the read channel (among
> other things), and a drive that turns on and seeks, then just spins
> (with a good bootable disk) is a sign of no read signal.
>
> If it isn't the '125, it could be a dirty head, misalignment (not
> likely unless a drive has been dropped), a bad analog board, or
> a bad cable.

Speed!!!!!!!!!!!!  Off-speed will cause the same exact issue.
And speed is the easiest of all problems to check and fix.  ;)

On Copy II Plus v9.1 there is a 'S-Drive Speed' checker under the
'Y-Verify' menu item. IIRC, it will tell you to put in a blank or
formatable disk, and if it is an Apple II Unidisk 5.25" drive, or
one that is compatible, you will find next to the front rubber foot
a small hole that you can access the speed pot thru with a jewelers
screwdriver. Gently turn it slowly one side to the other until the
program shows the speed within acceptable levels. I try to get it
right on, or one point high. All of my drives that I have set are
still good after years of service. I'm available via email if you
need help while you do this.

Bill