VT340 terminal faint screen problem

[stewart allen]

Hi all
i acquired 2 vt340 terminals: the screen for one of them comes on but is
very faint,so much that i can hardly make out what is on it. Is there any
way that it can be adjusted to be brighter or is there any website i can go
to to troubleshoot it. the other problem is related as this one does not
show any video although the indicator light shows that it is on. Of course i
use the two controls on the sides to no avail.

[Douglas A. Gwyn]

Post by stewart allen
i acquired 2 vt340 terminals: the screen for one of them comes on but is
very faint,so much that i can hardly make out what is on it. Is there any
way that it can be adjusted to be brighter or is there any website i can go
to to troubleshoot it. ...

You could get the maintenance manual, probably available
eventually through eBay. The brightness is adjustable,
and if you can't adjust it to an acceptable level then
there is most likely something wrong in the high-voltage
circuitry, which you should *not* attempt to work on
unless you're an expert (or just have a death wish).

If you know an experienced television repairman, he
might be able to troubleshoot these problems.

[Paul Brook]

Post by Douglas A. Gwyn

Post by stewart allen
i acquired 2 vt340 terminals: the screen for one of them comes on but is
very faint,so much that i can hardly make out what is on it. Is there any
way that it can be adjusted to be brighter or is there any website i can go
to to troubleshoot it. ...

You could get the maintenance manual, probably available
eventually through eBay. The brightness is adjustable,
and if you can't adjust it to an acceptable level then
there is most likely something wrong in the high-voltage
circuitry, which you should *not* attempt to work on
unless you're an expert (or just have a death wish).
If you know an experienced television repairman, he
might be able to troubleshoot these problems.

I fear it is more likely that the screen phosphor is at the end of
it's useful life. Cranking up the brightness preset (VT220, 320, 420)
is usually only a short-term fix and often causes the VT to blow
completely so I don't suppose the 340 would fair much better.

Regards,

Paul

My comments are my own opinion and not necessarily that of any
organisation.

[Douglas A. Gwyn]

Post by Paul Brook
I fear it is more likely that the screen phosphor is at the end of
it's useful life.

It is most unusual for the phosphor to degrade uniformly
across the screen face. Usually it fades on the left side
where most of the text has been displayed. If the whole
display is dim then the problem lies elsewhere.

[Paul Brook]

Post by Douglas A. Gwyn

Post by Paul Brook
I fear it is more likely that the screen phosphor is at the end of
it's useful life.

It is most unusual for the phosphor to degrade uniformly
across the screen face. Usually it fades on the left side
where most of the text has been displayed. If the whole
display is dim then the problem lies elsewhere.

I based my opinion on the past 16yrs working on a banking network
where the whole of the screen is constantly used, not just the l/h
side.