anyone have DEC (vt100) parts list?

[Dave Hiebeler]

Recently, my DEC VT100 died. When I opened it up, on board
"5014130 D-P1 / VT100 Monitor", a capacitor appeared to have burned
out. Unfortunately, I don't know what the values on the capacitor
are; when I opened up another (working VT100), that capacitor isn't
labeled (it just has a silver casing).

The capacitor has the label "C439" on the circuitboard; apparently
this is a DEC parts number. If someone has a DEC components catalog
and could look up what this capacitor is, I'd *really* appreciate it.
Alternatively, if someone knows of a DEC customer hotline I could
call, that would be good too, assuming they'd help me out. I'm
borrowing this terminal from a research lab in New Mexico, so it's not
practical for me to just let them deal with it. :-)

Thanks for any help!
--
Dave Hiebeler / Computer Science Dept. / Amos Eaton Bldg. /
Rensselaer Polytechnic Institute / Troy, NY 12180-3590 USA
Internet (preferred): hieb...@turing.cs.rpi.edu Bitnet: userF3JL@rpitsmts
"Off we go, into the wilds you ponder..."
--
Dave Hiebeler / Computer Science Dept. / Amos Eaton Bldg. /
Rensselaer Polytechnic Institute / Troy, NY 12180-3590 USA
Internet (preferred): hieb...@turing.cs.rpi.edu Bitnet: userF3JL@rpitsmts
"Off we go, into the wilds you ponder..."

[Forrest Cook]

In article <}{F#89^@rpi.edu> hieb...@cs.rpi.edu (Dave Hiebeler) writes:
> Recently, my DEC VT100 died. When I opened it up, on board

...

> The capacitor has the label "C439" on the circuitboard; apparently

Ah, yes, good old C439. I have been charged with keeping about 25 VT-100
terminals running for the last 5 years. In general, VT100s are wonderful
pieces of hardware and fail very infrequently, with the exception of
C439. Every VT-100 we own has had C439 fail at some time or another.
I have only had one logic board failure and zero power supplies fail to
date.

Here's my suggestion for fixing up your aging VT-100:

- As always, CAREFULLY discharge the second anode of the CRT with a grounded
screwdriver. BE CAREFUL, 10KV can kill you.
- Replace C439 with a 75 to 100 Microfarad capacitor rated from 50 to 100 Volts.
The original part may be as low as a 6 volt part.
- Replace R481, 100 Ohms, 1/2 watt or greater.
- Replace R110, 3.3K Ohms, 1/2 watt or greater.
- Resolder the pins on the two white plastic connectors leading to the yoke
and the flyback transformer. The solder joints frequently overheat and get
microscopic cracks around them.

By the way, the symptom you get before C439 fails completely is a white stripe
on the left side of the screen. When the cap fails, it may explode in a ball
of smoke or just poot out a bit.

If your CRT is dim and fuzzy, you can get a new one from DEC for around
$150.00. The kit includes a new CRT, video board, and flyback transformer.

--
^ ^ Forrest Cook - Beware of programmers who carry screwdrivers - LB
/|\ /|\ co...@stout.atd.ucar.edu WB0RIO (This posting is an OPINION)
/|\ /|\ {husc6|rutgers|ames|gatech}!ncar!stout!cook

[Michael Ardai]

In article <}{F#89^@rpi.edu> hieb...@cs.rpi.edu (Dave Hiebeler) writes:

(His Ball Bros. board popped the usual cap)

When that cap blows, it often takes the little white blob diode next
to it. Make sure you check this out.

>Dave Hiebeler / Computer Science Dept. / Amos Eaton Bldg. /
>Rensselaer Polytechnic Institute / Troy, NY 12180-3590 USA
>Internet (preferred): hieb...@turing.cs.rpi.edu Bitnet: userF3JL@rpitsmts
>"Off we go, into the wilds you ponder..."
>--
>Dave Hiebeler / Computer Science Dept. / Amos Eaton Bldg. /
>Rensselaer Polytechnic Institute / Troy, NY 12180-3590 USA
>Internet (preferred): hieb...@turing.cs.rpi.edu Bitnet: userF3JL@rpitsmts
>"Off we go, into the wilds you ponder..."

\|/ Michael L. Ardai ar...@bu-pub.bu.edu
--- ---------------------------------------------------------------
/|\ ...!sun!teda!maven.dnet!ardai (preferred)