VT100 and/or VT105 rescued from scrap

Jarratt RMA robert.jarratt at ntlworld.com
Tue Oct 20 17:29:45 CDT 2015

> On 20 October 2015 at 22:12 Ian Primus <ian.primus.ccmp at gmail.com> wrote:
> I can't seem to get the link to work with the pictures, so I don't
> know what the tube looks like, but sticky fluid is NOT an indication
> of a problem with the tube. Some tubes used a bonded safety glass, and
> that goo leaks out over time. But I've never seen a VT100 with such a
> tube installed. The most common cause of goo on the tube is going to
> be goo surrounding the 2nd anode connection (the suction cup). This is
> the plasticizers leeching out of the anode wiring, and gooing up the
> tube. The cable will be all sticky too. You can clean it off, I find
> that brake cleaner will dissolve it nicely. Just clean the area around
> the connection, don't clean the graphite coating off the main parts of
> the back of the tube - scrub only the clear glass areas.
> Without knowing what parts you have, I can't really tell you more than
> that, but, in general, I find that VT100's tend to work fine. There's
> nothing special I would do, just hook everything up and try it out.
> You're not going to blow anything up, assuming you've got parts
> connected properly.
> -Ian
> On Tue, Oct 20, 2015 at 12:11 PM, Lukas Kaminski
> <lukas.kaminski at krankikom.de> wrote:
> > Hello list,
> >
> > i got hands on several VT100 and VT105 parts. It SEEMS (at least to me)
> > to be one complete terminal without a power supply and some additional
> > parts. I took pictures of everything, which can be seen here:
> > https://antares.krankikom.de/index.php/s/vcIZuHbpsn3lSoL
> > (sorry for the self-signed certificate)
> >
> > I already found this interesting page:
> > https://github.com/bbenchoff/VT100Adapter, so i guess i have everything
> > to try to repair the VT100.
> >
> > But i never tried something like that, and i fear to break something as
> > soon i connect anything to power.
> >
> > How should i start? I especially don't know how to clean the boards,
> > check the eproms and i'm afraid that the CRT is broken, since it has a
> > sticky fluid on it.
> >
> > Bye,
> >
> > Lukas Kaminski

I couldn't get the link to work either, I could only get parts of the images. I
too saw leakage from around the anode cap. I have been advised to get all that
cleaned up (isopropyl will do I think), and then, iirc, re-grease the anode cap,
although I am not at home to check and I can't remember what kind of grease you
need to use for that.

I would be careful about just powering it on in case there is something bad
somewhere that blows a component that can't be replaced (I believe flyback
transformers fall into that category). So I would check all the PSU and video
control board electrolytic capacitors in particular, and probably re-form them.
I would also use a dummy load to test the PSU to make sure it is producing the
right voltages without too much ripple. Once all that checks out, I would power
it up one part at a time, leaving the video control board to last but one, and
then the tube (and flyback) to last. At least, this is what I did, and suffered
no ill effects, although I did have to re-cap the video control board to stop a
screen wobble.

My VT101 and VT102 were one of my rare successes, with a lot of help from
another list member though!



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