Re: Troubleshooting the disk drives in a 8296D

From: David Wood (jbevren_at_starbase.globalpc.net)
Date: 2004-11-22 06:28:42

I concur with the bad rom thoughts.  I dont know how closely related the
1541 kernal is related to this system's kernal, but the flashing indicates a
bad rom (or ram?) on the 1541.

At any rate, check the logic board for cracks and see if there's any
loose/bad components.

-David

On Sun, 21 Nov 2004, William Levak wrote:

> On Sun, 21 Nov 2004, Marko [iso-8859-1] Mäkelä wrote:
>
> > Remember the CBM 220 (a.k.a. 8296D) whose drive analog board was broken in
> > two halves?  Well, I ended up buying it, and thanks to Ruud Baltissen, the
> > system now has a healthy-looking analog board.  However, the drives still
> > do not work.
> >
> > When I power up the system, the disk status LED between the drive slots lights
> > red for a while (approximately 1 second), then green for approx. 1 sec, and
> > then it flashes red once very quickly.  The LEDs next to the drive slots
> > do not light up.
>
> This sounds like a ROM error as the initialization is not completed.
>
> > When I power up my 8250, the middle LED does approximately the same thing,
> > but when it blinks red quickly, also the two LEDs at the drive slots blink
> > once.
>
> This is the normal initialization.
>
> > The drive complains either READ ERROR or DRIVE NOT READY when I try
> > DIRECTORY.  The drive LED (next to one of the disk slots) remains lit,
> > even after querying the error channel, until I issue the "UJ" command.
> >
> > When I try to format a disk, the drive complains WRITE PROTECT ON, no
> > matter which way the disk is inserted, and no matter if I swap the drive
>
> The write protect switch is connected to a pin on the 6530.  This gate may
> be bad, or the line may be bad.  Check the switch itself.  It may be
> broken or jammed, or it may not be positioned right.
>
> > cables.  (For each drive, there's one connector for the R/W heads, and
> > another for everything else.  I suspected that it would be accessing the
> > R/W heads in the wrong drive.)
> >
> > I cleaned the R/W heads, but there was no visible dirt.  On the other hand,
> > many keys on the keyboard didn't work before I took the keyboard apart and
> > washed everything except the circuit board.
>
> 90 percent isopropyl alcohol is good for cleaning circuit boards.
>
> > Does anyone have any ideas where to begin troubleshooting?  Is the behaviour
> > of the LEDs normal?  I'd otherwise swap parts with my 8250, but the built-in
> > drive unit of the 8296D looks completely different.
>
>
>
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>


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