21 Nov
2001
21 Nov
'01
9:30 p.m.
On Thu, 22 Nov 2001, Tony Duell wrote:
I think the fuse was ok. I think I can get to this machine, and may pull
it out tonight. I'll check the chopper and related components.
-Toth
I have a non working 128k unit I'd sure like
to get around to fixing...It
actually worked before I located a keyboard and mouse for it, I think I
used the wrong type of keyboard cable. When I powered it up with the
keyboard, heard a snap, and it didn't work anymore :/
The keybaord port carries +5V, data (TTL level), clock (TTL level),
ground, in that order.
If the keyboard cable was made to swap the pins end-for-end (which some
cables do), it would swap over +5V and ground at the keyboard. The
keyboard won't like this!, and it may also have damaged the PSU inside
the Mac. My guess is that the logic board in the machine is still OK.
I would check the PSU outputs inside the Mac. And investigate the PSU. Is
the fuse still good? What about the chopper transistor. And so on.