Fortunately,
right angle DB9 plugs are readily available. But yeah,=20
desoldering that is going to be fun :D
This is probably a good point to ask: Does anyone recommend using a=20
hot-air reflow tool to desolder through-hole components like the DB9? My=20
experiences with desoldering guns have been universally poor. They seem=20
to make a mess of the PCB (lifted / torn traces) and seldom are able to=20
clear the holes sufficiently. The hope is that positive hot-air flow=20
would reduce the localized thermal shock while keeping all 9 pins above=20
the melt point while I pull it.
I've had great success using a nromal handheld solder sucker to remove
parts from PCBs without damaging either the part or the PCB. it's not
uncommon for me to desolder a ROM from a working machine in order to dump
it out, and then solder it back in place (actually, I'd problaby put a
socket in, but anyray).
I wouild recommend a temperature controlelr soldering iron a little
hotter than normal (I use a #8 tip in my Weller TCP). A fine tip too. I
also find that dismantling the solder sucker and putting a smear of
vaseline (petroleum jelly) on the washer helps a lot. As I mentioend in
an earlier posting, a new, find nozzle on the sodler sucker helps a lot.
When uou;ve remvoed the solder, try to wingle the pins ro break any
remaining bond before pulling the part out. This is easy to do on some
components, impossible on others. Don't force anything. Alas only
experience will tell you how hard you cna pull the compoonent without
riskingdamage to the PCB.
You may find you can cut up the old DE9F connecotr to remove the pins one
at a time. Maybe with a cut-off disk in a Dremel or simuilar.
1/4"
phono jack on the front of the computer. But, I'm actually thinkin=
g=20
it might be the foam discs in the keyboard. You
will also get that erro=
r=20
if you hold down any of the keys while turning on
the computer.=20
Therefore, if those little mylar discs have fallen off the foam, and ar=
e=20
> laying on the circuit board contacts, you could have the same effect.=20
Now that I wasn't sure of...
I would recomend taking the keyboard apart anyway and inspecting these
disks. You can then see if any are likely to be 'active'.
That means
"system software damaged". The "fix" is to boot from Lisa=20
Office disk 1, and do a repair. Of course, you'll need to disassemble=20
and clean your floppy drive, since it's sure to be gummed up and frozen=
=20
> with grease. The metal eject mechanism comes off easily (four screws=20
> from underneath, one jesus clip on the eject motor), so you can easily=20
> WD40 it to dissolve the old grease.
I wouldn't put 'Wanton Destruction 40' anywhere near the floppy drive (or
any other aprt of a classic computer). The stuff we get in the UK
contains some quite long-chain waxy hydrocarbons whcih will gum things up
after a short while.
I've never worked on a Lisa drive, but I've worked on plenty of the Sony
full-heigfht 3.5" drives, singel and double head, in HP units. They are
similar mechancially to the Lisa drive. Some of the odler eject
mechansims will come totally apart (the levers are held on with
E-circlips), which makes cleaning a lot easier. The later ones are
riveted, so you can just rmeove the springs, soak the assmebly in
solvent, then work the parts back and forth and wipe off the old grease
as it appears. I find propan-2-ol (isporpanol) woeks well for this.
There are some photos in my flickr acocunt (tony_duell I think, but
searching for HP9820 will find it) which show a Sony double-head drive
stripdown. Your drive is similar.
-tony