Dying VaxStation 4000 VLC - help?

From: Tothwolf <tothwolf_at_concentric.net>
Date: Mon Nov 18 12:20:01 2002

On Mon, 18 Nov 2002, Mark Tapley wrote:

> On disassembly:
> Toth wrote:
>
> > First you'll want to remove lower portion of the plastic shell. There
> > are 5 screws on the bottom of the unit, and two clips on the front
> > edge.
>
> Figured out how to release those. Stuff a flat-head screwdriver blade in
> from the bottom side, so it slides between the plastic clip and the
> metal tab it locks over. That way it's pretty easy to lever the plastic
> *only* far enough to disengage.

[Correction, there are 4 screws that hold the bottom cover on, the 5th
hole isn't used to screw the cover to the metal chassis.]

I have a collection of flat tools made from things like drive mounting
slides and slot protectors, one of which was nearly perfect for this.

> > Once the graphics board is out, there are 3 more phillips screws at
> > the back edge of the mainboard. The plastic clips pull up to release,
> > but with the bottom shell off, you can use something to push them up
> > from the underside.
>
> That works. I used the point of needle-nosed pliers as a pin-driver (set
> in place, hold the handles, use the other hand to hammer on the one
> holding the pliers). Once the pins were driven mostly out, the whole
> clip could be wriggled out with not too much trouble. I still hate those
> clips. What do they do that a screw and lockwasher wouldn't do better?

I used another one of those flat tools I mentioned above to push the pin
up, then just pulled it the rest of the way out my hand. Those clips in
some ways are better than screws. They are very fast to install, and won't
come out on their own. Of course, beings as the VLC was built low cost,
that might also have had something to do with DEC deciding to use those
clips. I have some rack-mountable gear that uses similar clips that have a
larger diameter to mount their front panels. It makes it very easy to
remove the panels to change settings or troubleshoot.

> Big help! Thanks! I had the motherboard out in my hands last night, so
> I'm ready to go to work desoldering either the comparator or the
> resistors. Anyone have any educated guesses which one to try first?

No idea. Have you checked the solder joints and connections between
components with an ohm meter? That might help turn up any problems.

-Toth
Received on Mon Nov 18 2002 - 12:20:01 GMT