Re: Technical question... continued !

[buggie@musca.unm.edu (stephen e buggie)]

If the Disk II interface card is inserted or removed WITH POWER ON, the
74LS125 chip will explode, filling the room with the "baked Apple" smell
of cooked electronics.

Check also the medium-sized capacitors on the Disk II analog board.  They
are less likely than ICs to fail, but when they do, the metal canister
looks bloated.  Just swap the capacitor from a junked analog board.


I REPAIR DISK II DRIVES:   Flat rate of $5 per drive plus shipping.  (No
cost if IO dont succeed, other than shipping).


Steve Buggie
200 College Rd.
Gallup NM 87301				buggie@unm.edu





Patrick Schaefer (pa.schaefer@fz-juelich.de) wrote:
: eib wrote:

: > 1) The Apple II does not boot. It makes a sort of "bi....bi....bi..."
: > noise, like a short boot beep that loops.
: > 2) The Apple boots, and the drives load nothing (the red light is lit,
: > but it does not read the disk).

: You plugged in the drive cable the wrong direction (180=B0 rotated). This=

: will kill the 74LS125 and the ULN2003/XR2003 on the Disk ][ Analog
: Board. Try booting for some time and you'll see some smoke coming
: outside the drive. This is the 2003 chip.

: Replacing the chips is easy. Get a new one from your local electronic
: shop, remove the old chip from its socket and insert the new one. With a
: working 2003 you should be able to move the RW head ('PR#6' -->
: 'grrrzzz'), the 'LS125 is required for read/write operations.

: Patrick