From: William Levak (wlevak_at_cyberspace.org)
Date: 2004-11-22 02:10:35
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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