Asteroids Graphic Glitch

mwiggett

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Donor 4 years: 2020, 2023-2025
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This is an Asteroids -05 version board. There was no complaint about this but it's driving me nuts trying to figure out what is causing this. I have replaced both DAC's, the TLO81's, 82's, and 4016's. Nothing has changed this. I'll take any advise right about now. It also is not my monitor. Pic is what I see on the test screen. Here is the link to the video of what I see. https://forums.arcade-museum.com/media/img_0059-mp4.24547/
 

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Are they potentially some off brand? or are the TL082s not TI chips? I've also seen off brand chips in that area do dumb things..
No they aren't off brand. I didn't induce this glitch by replacing anything. Glitch was always there.
 

Looks like the exact same issue.
 

Looks like the exact same issue.
I agree. Unless I have a bad one that I installed that just happens to have the same problem, that would be a big coincidence.
 

LyonsArcade did a fix on this exact issue pretty sure.

Lucky for me i've been binging all their asteroids repairs despite not and probably never owning an asteroids lol.
 
As strange as it sounds, I did have a bad 4016. Funny thing is, they work fine in a different board.
 
As strange as it sounds, I did have a bad 4016. Funny thing is, they work fine in a different board.

It might not actually be the 4016 in that case.

It might be something related to the +8.2 and -8.2 circuits (or something else that interacts with the 4016's), which is interacting with the 4016's.

I call these 'system level' issues, meaning they are caused by the interaction between multiple parts. Replacing one part makes the problem go away, but not necessarily because that part is the problem. Due to natural tolerances and variation, the interaction between two or more parts can make a problem come or go when you switch other parts.

If you put the 4016 in another board, and that board is configured the same way (i.e., in the same position and with the screen invert configured the same way), then the 4016 might not be the problem. Also, 4016's are 4 switches in one. So you have to put it in the same location and with the same screen invert to compare apples to apples. Else one of the switches in the package can be bad, but the others can be ok.
 
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