More on my flickering DEC monitor

From: Witchy <witchy_at_binarydinosaurs.co.uk>
Date: Tue Mar 23 13:58:24 2004

> -----Original Message-----
> From: cctalk-bounces_at_classiccmp.org
> [mailto:cctalk-bounces_at_classiccmp.org] On Behalf Of Paul Koning
> Sent: 23 March 2004 19:37
> To: cctalk_at_classiccmp.org
> Subject: Re: More on my flickering DEC monitor
>
> I'd say either those components shown in solderside.jpg were
> replaced at some point, or the person doing the
> hand-soldering wasn't particularly competent. More likely
> the latter since the signs are there at every pin that's a
> hand-soldered part, as far as I can see.

It could be; I rescued the monitor from the dumpster queue after the
previous user had complained that 'the colours were all fuzzy'. A quick
adjustment of the Purity control sorted that out :)

It's possible it's been repaired in the past too.
 
> Look at D910 (a bit further to the right on that photo) for
> an example of good work. (I think that one is the wave
> solder machine at work...)

'K
 
> normal use. Raising them -- and high current diodes like
> D907 -- off the board is a typical trick to get better
> cooling. The radiated heat tends to discolor the board at
> some point, that isn't necessarily an issue.

Right - that makes sense.....
 
> Something to look at, though: on the "solder.jpg" picture I
> wonder about the funny rings on the right solder joint of
> R923 and R924.
> That may just be a shadow, or it may be a mechanical problem
> in that joint. It wouldn't hurt to find joints like that and
> re-melt them.

It's not shadow, that's what made me ask in the first place....I've now
remade all the large joints like that and I'm in the process of putting the
whole shebang back together.

Ta! If you hear a bang in the next half hour you'll know what it is.....

--
Adrian/Witchy
Owner & Webmaster, Binary Dinosaurs
www.binarydinosaurs.co.uk - possibly the UK's biggest online computer museum
www.snakebiteandblack.co.uk - ex-monthly gothic shenanigans :o(
Received on Tue Mar 23 2004 - 13:58:24 GMT

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