25 Sep
2013
25 Sep
'13
7:06 p.m.
On 9/24/13 12:47 PM, Ethan Dicks wrote:
Present state: machine gives "bong" when
turning on (it always did),
usual screep wipe happens, then the "[?]" disk icon flashes. I have
one 400K drive, an OA-D34V-22, and (for now), Rev A ROMs. This
combination does not work. It tries to read disk, ejects it, then
asks for another one. I already have the -B ROM images and just need
to burn a pair of 27256s since that's an easier path than locating a
working, original revision OA-D34V drive mech. On the OA-D34V-22 I do
have, it did require removing petrified grease from the old eject
mechanism. I have some white lithium grease I'm contemplating using
unless there is some magic grease the job requires.
http://support.apple.com/kb/TA34190?viewlocale=en_US
PROBLEM DESCRIPTION: When running MacTest with a 400K drive
the test says that the drive has failed.
CAUSE: Possible incompatability between the drive and the boot
ROM on the Macintosh. There are two revisions of stepper motors for
the Macintosh 400K drive.
One of them, is compatible with any rev of ROM on the Macintosh.
The other is not compatible with revision A. It is only compatible
with revisions B or later.
CURE:
1. Remove the drive case and examine the drive mechanism.
Locate the label on the drive's stepper motor. If the label is
circular and on the flat end of the stepper motor facing the rear
of the drive, then the stepper motor is compatible with any rev of
Macintosh boot ROM and if the drive fails MacTest, it should be
replaced .
2. If the label is square and on the curved part of the stepper
motor, then you need to check the ROM in the Macintosh to make
sure it they are revision B or later. A square labelled stepper motor
is not compatible with revision A ROM in the Macintosh. If the
customer's Macintosh has revision A ROM installed, install revision B
ROM to make it compatible with the disk drive.