Viewsonic Optiquest Q71 Monitor Problem

I am hoping there is someone here familiar with the internals of a
Viewsonic Optiquest Q71 Monitor. This one has very specific symptoms:
1) display is too bright
2) onscreen menu brightness control has no effect
3) display has white lines across it about 1 inch apart, sloping upward
to the right
4) one time only in last few weeks it produced a very good quality
picture when turned on, has not done it since.

Because of #4 I am hoping it is just an internal adjustment needed.
It's probably not worth replacing parts. Made in 1999.

Thanks for any help.
Dave

<post2news1@yahoo.ca> wrote in message
news:1120328235.627204.209260@g43g2000cwa.googlegroups.com...
>I am hoping there is someone here familiar with the internals of a
> Viewsonic Optiquest Q71 Monitor. This one has very specific symptoms:
> 1) display is too bright
> 2) onscreen menu brightness control has no effect
> 3) display has white lines across it about 1 inch apart, sloping upward
> to the right
> 4) one time only in last few weeks it produced a very good quality
> picture when turned on, has not done it since.
>
> Because of #4 I am hoping it is just an internal adjustment needed.
> It's probably not worth replacing parts. Made in 1999.
>
> Thanks for any help.
> Dave
>
Well a google shows it's a 17" CRT monitor - apparently still being sold
by Tiger Direct, at least, for about $145.
The symptom is typical of having lost the retrace blanking - and more
likely is due to a component failure (maybe a capacitor opened up)
than any adjustment. Blanking (and BRT control) is typically inserted at G1.
Since on screen BRT has no effect, it could also be a fault internal to
the tube itself, or an indication that the connection to G1 has been "lost".
The (slightly) internittent nature would tend to indicate an open
connection
somewhere - likely on the "neck board". May even be a cracked trace.
Could be oxidation on the tube pins, but that's less likely.

Either way, it would require the service of an expert to diagnose & repair.
Replacing the tube is likely not at all economically feasable - finding an
open circuit, &/or replacing the correct capacitor might be... Only one
way to find out . . .

Regards,
NGA