RE: Go8 Heater issues

Does anyone know what voltage you should be reading on pin 7 of the yoke?
I'm getting about 170v, which I suspect is too high. The main problem I'm
having is the brightness is a little too high and the picture is too big.
I have the x and y size and the brightness turned all the way down. Just
for testing purposes, I've adjusted the R933 POT and was able to reduce
the picture slightly - so I'm suspecting there's a bad component somewhere
along the brightness circuitry.

Any advice would be cool.

Matt

_____________________________________________________________________

On Mon, 1 Mar 1999, Todd Miller wrote:

> I have noticed a similar problem in my Space Fury,
> It's more like expanding as it doesn't do it all the time.
> During normal game play the display is fine. It's most
> noticeable when the screen is blank, then when a image
> is displayed, it expands outward into place, from the
> center in all directions (maybe ½ inch of 'growth') it
> doesn't expand beyond the screen boundaries like most
> HV problems cause. It's dependent on what is displayed,
> I don't notice it in Space Fury, but when I play Eliminator,
> it's noticeable (I think it's because of the three line boarder
> around the play field) Anyone have an idea ? One of these
> days I'll crack down and buy a HV probe, maybe this would
> help to diag these HV probs.
>
>
> Todd Miller, LAN Analyst
> Ron Weber and Associates
> 103 E. State Street, Mason City, IA 50401
> (515)423-4293/(515)423-4594 FAX
> http://www.telethinking.com
>
>
> -----Original Message-----
> From: Mark E Davidson [SMTP:Burbs1@concentric.net]
> Sent: Friday, February 26, 1999 8:05 PM
> To: vectorlist@mcfeeley.cc.utexas.edu
> Subject: Go8 Heater issues
>
> My Go8 in my Star Trek is freeking out upon power up.
> I know the voltage heater for the tube comes out of the HV unit
> But what
> this set is doing is going bright and dim and the picture is
> shrinking and
> expanding as the machine runs. The reason for all this is
> because the
> heater voltage is changing. You can actually see the filaments
> change
> from hot to cooler as the monitor runs and there is also changes
> in the
> typical high voltage sound that all monitors make. Where do I
> start in a
>
> repair? Ideas?
>
>
Received on Mon Mar 1 11:59:58 1999