3 Apr
2011
3 Apr
'11
12:26 p.m.
On Sun, 3 Apr 2011, Mr Ian Primus wrote:
Good point. I'll try that.
Yup. Just about to start this exercise. The original grease has turned
into gunk.
--- On Sun, 4/3/11, Steven Hirsch <snhirsch at
gmail.com> wrote:
This is probably a good point to ask: Does anyone recommend using a
hot-air reflow tool to desolder through-hole components like the DB9? My
experiences with desoldering guns have been universally poor. They seem
to make a mess of the PCB (lifted / torn traces) and seldom are able to
clear the holes sufficiently. The hope is that positive hot-air flow
would reduce the localized thermal shock while keeping all 9 pins above
the melt point while I pull it.
I cleaned things up enough to get the self-test
and startup
to run.? The DB-9F mouse connector is effectively
destroyed from the battery electrolyte.? If I wiggle
the connector the mouse is operational, though. A good
sign.? Not looking forward to pulling the old DB9
right-angle connector from the motherboard...? This one
is too far gone for cleaning and will definitely need to be
replaced.
Fortunately, right angle DB9 plugs are readily available. But yeah,
desoldering that is going to be fun :D At the end of
the internal self-test (everything passes!)
it complains that the keyboard is not plugged in.? I
get this result with both keyboards.? Is that the
symptom of dead foam disks?? Somehow I thought it would
still know a keyboard was out there, so perhaps this is
something else altogether.? There was so much corrosion
on the edge connector at the rear of the CRT cage that it
could simply be bad contacts at that point. Will have to
start checking continuity.
It could very well be corrosion/tarnish on the edge connector, or at the
1/4" phono jack on the front of the computer. But, I'm actually thinking
it might be the foam discs in the keyboard. You will also get that error
if you hold down any of the keys while turning on the computer.
Therefore, if those little mylar discs have fallen off the foam, and are
laying on the circuit board contacts, you could have the same effect.
Try holding the keyboard upside down and shaking it, then turning on the
computer with the keyboard upside down (and no keys pressed). The one
ProFile drive that comes ready tries VERY hard to
boot, but eventually fails with an error 10707.? This
is after a considerable amount of access, so something is
almost alive there!
That means "system software damaged". The "fix" is to boot from Lisa
Office disk 1, and do a repair. Of course, you'll need to disassemble
and clean your floppy drive, since it's sure to be gummed up and frozen
with grease. The metal eject mechanism comes off easily (four screws
from underneath, one jesus clip on the eject motor), so you can easily
WD40 it to dissolve the old grease. If you need software, it's readily available in
the form of DiskCopy
images. Remember - use DiskCopy 4.2, not 6.3. Any older Macintosh with a
built in floppy drive can write Lisa disks, although a Mac running
System 7.5 or older is usually preferred. The use of an 800k or 400k
drive to write the disks is not required - the Macintosh 1.4mb drives
work fine too.
Already grabbed it - thanks!
Steve
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