[Coco] FD-50X Drive manuals

[Bill]

	6- bad media? Are you formatting HD floppies? Does the problem
persist on different media?
As a matter of fact, they ARE _HD_ floppies. Certron MD-2HD, to be precise.
It's been so long since I even thought about them, I didn't put two and two
together. If anyone had a spare floppy drive (or several), I'd appreciate
the loan of one.

> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-
> bounces at maltedmedia.com] On Behalf Of Mike Pepe
> Sent: Sunday, March 08, 2009 12:37 AM
> To: CoCoList for Color Computer Enthusiasts
> Subject: Re: [Coco] FD-50X Drive manuals
> 
> Bill, hope you said some extra prayers, I think your CoCo collection is
> possessed!
> 
> A couple of things to note:
> 
> 1- you can't exclude a problem with the CoCo itself at this point
> 2- The old full height TP drive is probably a lost cause due its many
> mechanical and analog adjustments. I wouldn't bother with it just yet
> 3- The FD502 service manual is useless without a ton of specialized
> equipment.
> 4- The stepper motors are bi-phase, so when you say you hear 18 clicks
> you may be hearing 35 tracks, but only every alternate step is audible.
> 5- The round FD502 cables are subject to failure. I've seen a couple of
> broken ones so far. The flat ribbon cable may be bad also, but I doubt
> all 3 cables are bad in exactly the same way.
> 6- bad media? Are you formatting HD floppies? Does the problem persist
> on different media?
> 
> I would open the covers up on the 502's and watch the show. Most
> importantly if the head restores itself to track 0 once the format
> process is completed.
> 
> The format process is pretty much blind. As long as the controller is
> seeing index pulses from the drive there's really nothing I can think
> of
> that would cause it to bomb out in the middle of the process (other
> than
> loss of index pulses) 
co