[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