Asteroids Shrink/Expand Issue

FrizzleFried

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I have two problems with one of my Asteroids. It has a slight shake to it and it has a strange expansion/shrinkage issue. I posted a video of the issue on you tube right here:

http://www.youtube.com/watch?v=GmMbBHq-WVo

Can anyone give me any suggestion how to rectify one or both of my issues? I've already re-capped the chassis. I also dropped in a new big blue in... No help for either issue.

Thanks!
 
I have the exact problem on mine, it moves up and down with the sound?

I was going to start looking there, turn the sound off and see if it stops.

My thinking was there was interference from the magnetic field from the speaker

Is yours possibly that?
 
a slight shake

mine had similar symptom for like a second or two, then the screen would stabilize for a bit and then shake again for a second or two, then stabilize again.
seemed like it was a random amount of time in between shakes too. i write this because my computer is having trouble downloading videos for the past week or so, and i cant see exactly if your "a slight shake" is what was happening to me.

i replaced ALL the electrolytic capacitors EVERYWHERE i could find them (like i do to every game that finds me) on my ASTEROIDS. if you were to hold a gun to my head, and ask me to choose which one cured that problem, i would guess it was one of the electrolytic capacitors on the GAME BOARD PCB that fixed it.

i think replacing caps on game boards is kinda like vehicle owners' manuals.
hardly anyone ever reads them.
 
I have two problems with one of my Asteroids. It has a slight shake to it and it has a strange expansion/shrinkage issue. I posted a video of the issue on you tube right here:

http://www.youtube.com/watch?v=GmMbBHq-WVo

I didn't see the display shaking in your video. As far as the expansion/shrinkage issue, I would guess that can be resolved by adjusting the linearity pots on the monitor. What monitor do you have in there? 801? 802?
 
I didn't see the display shaking in your video. As far as the expansion/shrinkage issue, I would guess that can be resolved by adjusting the linearity pots on the monitor. What monitor do you have in there? 801? 802?

802... where be the linearity pots? And yeah, you can't tell teh shake in the vid. The shake is actually very small fluctuations in vertical size..when it shakes downward at the top, it's shaking upward at the bottom (squeezing toward the middle)... only a pixel or so shake.
 
The slight shake may be coming from linearity pots but if you're getting vast amounts of image bloom, you're HV diode is bad.

Chris, take a close look at the video. It doesn't really look like blooming from what I see. Looks like more of a cap issue. *shrug*
 
if you have a scope check the b+ for a ripple it seems as if the more objects you have on the screen the more it shrinks could be a problem in the regulator circuit
 
so what do you guys think he should do first? adjust the lin pots? cap the board? replace the hv diode? Even though adjusting the lin pots can be a pain in the ass, it seems to be the easiest thing to do ... plus he may find out if the lin pots are causing the shaking issue ...

the lin pots can be found on the deflection board ... there is two per channel and they should be easily identifiable since they will most likely have some type of glue holding them in place with ... before adjusting them I would make the location of each pot ... before going any further you may want to review the docs below ...

http://arcarc.xmission.com/PDF_Moni...Electrohome G05-802 G05-805 Monochrome XY.pdf

http://arcarc.xmission.com/PDF_Monitors/FAQ Black and White XY Version 1.1 dated 7 Feb 02.pdf
 
pain in the

seems like hes saying the more objects on screen, the smaller the image. cold solder joints on the game PCB might/would inhibit electron flow when more electron flow was required for the more objects, shrinking the image.

the capacitors need replacing anyway,
and its fun crossing potential problems, off the troubleshooting list.

as for DOKERT. i like it when he helps me with my problems.

i dont see him as a post padder, but who knows with that post.
 
After dinking around with the linearity pots a bit I got it where it looks damn near perfect and the shaking stopped as well! W00t!
 
After dinking around with the linearity pots a bit I got it where it looks damn near perfect and the shaking stopped as well! W00t!

very good ... if the pots were causing the shaking this problem will most likely return ... I wouldn't worry about it until it does ...
 
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