G05-802 Spot killer AND Video?

Malice95

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G05-802 Spot killer AND Video at the same time?

So I have a capped G05-802 with one of Bob's kits. Everything looks
great with the monitor.. video is nice... except for a spot in the exact
center of the screen. Adjusting the brightness and contrast controls
makes it change but it never actually goes away. Its like the spot killer
is running at the same time as the video. The spot killer led on the chassis board is not lit.

Asteroids, ships, everything else looks normal. I adjusted the brightness
so there are no ray traces or trails behind moving objects.

Ideas?

Thanks,
Malice95
 
Last edited:
Okay.. wierd

I turned the machine off, came inside to type this up.. went
back out one more time and the spot was gone.. no issues now.
Video is great. Not sure if I have a problem or not now.. wierd.

Malice95
 
All right I definitly have a problem somewhere. Played the game
for 15 mins.. everything looked great and then the spot came
back out of the blue while between games.

Thoughts?
 
It may be a board issue..

If I play a game for a bit after power on it looks good..
then after the game is over, the spot shows up instantly.
I replicated this twice.

Play another game with the spot... when I reach the high score
screen to enter my initials the spot goes away. Finish entering
my high score and go back to the attract screen.. spots back.
I replicated this twice as well.

Malice95
 
You are right.. I swaped the boards between the two asteroids I have and
the spot issue stayed with the monitor.

Any idea where to begin looking in the HV section? I didnt touch anything
in there when the chassis was capped.

Malice95
 
Another issue I just noticed is the screen size is smaller then
my other machine.. Its maybe 15-20% smaller. It doesnt fill the
whole screen. The text doesnt seem deformed .. just everything is
smaller.

I dont see any adjustments for that. what could cause that on a
asteroids vector?
 
Thanks Dokert.. I found the XY pots on the board schematic. I'll mess
with them when I get home from work.

Any suggestions on where to go with the spot issue? Next, I am going to
try swapping the chassis boards to isolate if the spot i being caused
by the chassis or the HV section/Chassis transistors.

Mike
 
Just a thought, but does your power cord have the ground lug still on it?

I have a similar issue with my Star Trek. It is very sensitive to grounding. I have a center dot issue with it as well and it's pointing to a ground issue.

Just a thought...
 
It does have the ground lug. So I realized that a deflection board swap is not possible. Both monitors are the same model but have slightly different
board wiring I guess atari bought from multiple sources for its B&W 19" quadrascan vector monitors.

So I guess I'll pull the bad monitor and start checking out the HV cage.

At least the one burnfree monitor looks great:)

Thanks so far.. more to come.
Malice95
 
Your brightness is up too high. Turn both down all the way. Put in test mode. Turn up brightness until just start to see a little of the intensity lines. Then increase contrast to see the whole screen. If the center dot reappears, turn the contrast down a little.

Make sure that the monitor is on for 15 minutes or so before you do this. The spot intensity will not show when it's cold.

I had the same problem on mine and was able to adjust it out.

Good luck.
 
Your brightness is up too high. Turn both down all the way. Put in test mode. Turn up brightness until just start to see a little of the intensity lines. Then increase contrast to see the whole screen. If the center dot reappears, turn the contrast down a little.

Make sure that the monitor is on for 15 minutes or so before you do this. The spot intensity will not show when it's cold.

I had the same problem on mine and was able to adjust it out.

Good luck.

The intensity lines you refer to, is that the graded pattern thing in the middle of the test screen? I have what sounds like the same problem as the OP. I tried adjusting the brightness and contrast, but will try your method. The odd thing is, the dot disappears when the high score screen is on, only comes on when the game or demo is running.
 
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