Sun Monitor Tuneup - how?

From: Sunny (sunny_at_nospam.net)
Date: 01/06/05 

Date: Thu, 06 Jan 2005 00:05:12 -0500

I recently acquired (from the dumpster) several Sun Microsystems 20"
monitors, model GDM - 20D10, which appear to be Sony Trinitrons on the
inside. They are really nice when working properly, but were
manufactured in 1994 so probably aren't worth sinking $ into.

I'd like to get two of them running to upgrade the 17" pair I'm
currently using.

One worked reasonably well as-is, but was unusable due to severe CRT
burn-in. The others had symptoms ranging from collapsed display to
failure to power on at all.

I made inquiries about professional repair, but nobody was willing to
provide even a diagnostic estimate - they said the chassis is
unreasonably difficult to work on.

I decided to have a go myself, and experienced the difficulties first
hand - the internals are completely surrounded by multiple layers of
metal shielding, with circuit boards mounted to the inside of the
shields all over the place. It takes almost an hour of disassembly just
to check the power supply fuse, and close to another hour to dismount
boards and arrange them such that one can apply power and take
measurements with any degree of safety.

Without going into tedious detail, I've swapped parts around and now
have two working monitors with good CRTs. One is almost perfect, except
for a slight "shimmer" (not sure how else to describe it), while the
other is sharp but exhibits faint retrace lines and has the display
offset to the left about 1/2" further than can be corrected with the
remote control.

It seems to me the remaining problems are minor and could probably be
corrected via internal adjustments, but there are a *lot*, mostly
unlabeled, and I'm well aware that fiddling with them to see what effect
they have is not the recommended approach. Looks like these monitors now
just need a good "tuneup".

Any suggestions on next steps? - given that obtaining a service manual
is highly unlikely, the professionals aren't interested, and my
electronics knowledge doesn't extend much past digital logic circuits?

TIA

Sunny

Relevant Pages

  • Sun Monitor Tuneup - how?
    ... failure to power on at all. ... metal shielding, with circuit boards mounted to the inside of the ... have two working monitors with good CRTs. ... corrected via internal adjustments, but there are a *lot*, mostly ...
    (comp.sys.sun.hardware)
  • Re: Sun Monitor Tuneup - how?
    ... > equipment to be difficult to repair, Im guessing they apply dummy circuits ... > You know about high voltage thats still in the chassis even after the power ... put more running monitors close to it. ... >>metal shielding, with circuit boards mounted to the inside of the ...
    (sci.electronics.repair)
  • Re: Sun Monitor Tuneup - how?
    ... > equipment to be difficult to repair, Im guessing they apply dummy circuits ... > You know about high voltage thats still in the chassis even after the power ... put more running monitors close to it. ... >>metal shielding, with circuit boards mounted to the inside of the ...
    (comp.sys.sun.hardware)
  • Found some BBC Micros
    ... My friend and I acquired six BBC Micros on the weekend, ... looking caps in the power supplies, so we tried plugging them in. ... Alternatively is anyone interested in these and/or the monitors? ... Can normal PC 5.25" floppy drives be used with these? ...
    (comp.sys.acorn.hardware)
  • Re: Crash
    ... The Power Supply is a 12000 Watt TruePower Quattro by Antec. ... I have not 'Blown' monitors, I run two monitors and they both go to 'Black Screen' even though the computer seems to be working. ... Since you are running high end games, I'd suggest getting a high rated power supply since your high end hardware needs more power. ... I'd check to make sure if the video card has any power connectors on it and ensure that it has a power connector plugged into it. ...
    (microsoft.public.games)