16 Oct
2015
16 Oct
'15
9:46 a.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Peter
Coghlan
Sent: 15 October 2015 23:47
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Opening a DECserver 90M External PSU
Back in April, I wrote:
> Robert Jarratt wrote:
> >
> > One of my DECserver 90M PSUs got dropped and stopped working as a
> > result, possibly because it got pulled by the cable. That sounds
> > like the kind of damage that might be repairable. I tried to open
> > the enclosure and I found a hole under one of the labels, expecting it
to
be
a screw hole, but it isn't.
> > I am guessing you just have to pry the halves apart, but without
> > knowing where the clips are inside it is easy just to break the thing.
> >
> >
> >
> > Does anyone know how you open these PSUs?
> >
>
> As far as I recall, there are no clips - it is glued all the way around.
>
> Mine (actaully a 90TL, with H7082-AB PSU) failed too. Using a lot of
> patience, I pried it open without too much damage, fixed it (a
> capacitor in the startup circuit IIRC) and glued it back together.
> The end result was only slightly rough looking and would probably have
been
better with a more suitable glue.
glue I
The thing has a very Lego-like quality about it.
It failed again some time later and I haven't had the enthusiasm to
break it open again since.
I finally worked up the enthusiasm. It was easy to open this time as the used to put it back together last time was not so
good. While I was
measuring
voltages on the input side, out of the corner of my
eye I noticed the LEDs
on the
front of the terminal server lighting up briefly. I
found that I could
get them to
light up consistently by pressing a meter probe on one
of the legs of the
chopper transformer and after deploying the magnifying glass, I found a
tiny
crack in the print leading to it.
That was a lot easier than I thought it was going to be. I hope it lasts
a bit
longer this time though.
Now I find that the privileged password is not what I thought it is...
Regards,
Peter Coghlan.
I tried to pry mine open, but it seemed that if I kept going I would end up
damaging it more than I would like. Do you have a picture of the opened
casing I could see? That would help me to see how best to open it.
Thanks
Rob