[rescue] urgent need for Sun Hi-Res monochrome monitor (or re pair assist)

[rescue at sunhelp.org]

Hi-
I have a monochrome 900x1152 that whined and I replaced the flyback
transformer which fixed the problem.  This was documented somewhere on the
web, but was years ago, and I'm not at home at the moment.  If you need more
help, drop me an email.  
David

-----Original Message-----
From: rescue-admin at sunhelp.org [mailto:rescue-admin at sunhelp.org]On
Behalf Of Greg A. Woods
Sent: Sunday, August 18, 2002 10:34 PM
To: Sun Rescue List
Subject: [rescue] urgent need for Sun Hi-Res monochrome monitor (or
repair assist)


I have three Sun Hi-Res monochrome monitors.  Two 365-1007's and a 356-1047.

I believe one's a Displaytek model on the inside despite the Sun model
number on the back, and the others are Motorola's.  LS7211S-Y01 and
L7201S-Y01 (I've no idea what the difference is, though the ones I have
range in age from 1988 to 1990).

Unfortunately all three are now non-functional.

That leaves me with an aging Samsung SyncMaster 6c that I can't stand to
use for too many hours, and an NCD 19c that's just too low a resolution
for much text and coding work, at least for my eyes.  I really need a
working hi-res mono monitor for my Sparcstation as I can't yet afford to
replace my main desktop with anything equivalently easy on my eyes
(though a Sun AM-TFT-LCD 24.1" monitor or equiv. would sure be nice! :-).

One unit may be relatively easy to repair -- the fuse pops instantly
when power is applied, and after pulling the SMPS module out and putting
it on the desk I watched sparks jump out as it blew yet another fuse.
One of the electrolytics may be dry, and perhaps one of the diodes is
shorted (there's even a bridge that gives low resistance readings in all
directions while in-circuit).  If I can find suitable test loads I may
try fixing this one on the bench, but I must say I'm no expert in SMPS
troubleshooting (though I've recently read about all there is to read on
the subject on repairfaq.org and other referenced sites).  I doubt I
have enough good replacement parts in my "shop" though so it really
would be nice to know what I need to buy before making many trips to the
store.....

The other two exhibit what is apparently a classic failure mode where
the SMPS makes an ever-repeating whining clicking noise.  One would
eventually "warm up" and work, but as of this morning it now makes a
fainter and faster cycling noise which takes quite some time to fade off
after the line power is removed.

(more about these symptoms in my resent <port-sparc at netbsd.org> posting)

I have friends locally who have more non-functional units (most with the
whining clicking symptoms, IIRC).  (I may even have a couple of the
grey-scale 1152x900 mono models that do the same.)

If anyone in the Toronto, Ontario, Canada area (eg. max 3-4 hr. drive
each way) has a spare, or parts for one, available, please contact me as
soon as you can.

If anyone has schematics for them, or knows where to find them for
certain (none of the obvious sites have them, such as electronix.com),
please let me know -- I've got more talented technicians to help, but
schematics would really help a lot.  I've almost worn google out looking
for information -- there just doesn't seem to be any out there.

If anyone has successfully repaired the whining clicking problem, please
share!

FYI the SMPS module is a little 5x6.5" motorola board labeled PSM-7458.
I can apparently order one of those for $20 from:

	http://www.neiparts.com/cmparts/brand/sun/sun4.php

but should I?  -- i.e. is that all that's busted?  will it be a waste of
$20[usa] plus shipping and duty and taxes plus delay when a $2 capacitor
is all I need?  (they have other parts -- I could probably use a new
horizontal board for one of the units as IIRC it was way out of
adjustment last time it worked)

Having three working units again would be wonderful -- it would make me
want to source out another MG1 card so I could have a second functioning
workstation in the basement too!

-- 
								Greg A.
Woods

+1 416 218-0098;            <g.a.woods at ieee.org>;
<woods at robohack.ca>
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