Tony Duell wrote:
before you go any further, have you checked all the
CRT voltages? I guess
you didn't do what I do, and measure/record them when the unit is new, so
as to have somethign to compare against. But you might be able to spot
any that are way out...
Unfortunately this was a freecycle acquisition, so not one
I'd had from
anything like new - the picture was already pretty dim when I got it, but
seemed to get worse after just a few hours of use. Nothing lost really if it
It's a pty you didn't measure th voltages as soon as you got it, and then
again wuen it had got even worse....
Yes, hindsight and all that :-) I really should have, because it was obviously
I know... FWIW, there are plenty of times I've not realaised I should
have measured something or whatever until it's too late...
unwell right from the start, although at first it was
perfectly usable, just
with the controls set far higher that what I would have considered "normal".
After a while though it went downhill, until brightness set at 100% was still
'too dark'.
What is a 'while'? I am suprised a CRT would loose emision as quickly as
you imply, and wonder if there's some other fault.
Is this
monitor new enoguh to have automatic grey scale tracking?
Hmm, yes it apparently does... (via a TDA4886 IC)
OK, you should be able to get a data sheet on that...
If this works like most grey scale trcking ssytems, it turns on the beams
just off the top of the screen and measures the beam currnets. And then
adjusts the A1 and video gains to compensate for the electron gun
characteristis.
What if that was mulfucntioning? Oftne these things use capacitors as
analogue storage elements to store the various parameters during the
scan. What if said capacitors were failing?
-tony