Tempest help needed

I would socket and replace the two 13201 switches in the video section next.

I've seen cases similar to yours, with what I call 'tiki-looking' text, which were caused by bad 201's. It could also be a bad 1495, but I'd start with the 201's.
I socketed the 201's and the 1495's and installed new chips but the same picture. I scoped all the signals backwards from x/y test points to 74ls194's compared them to working boardset and see no difference. I must be missing something or doing something wrong
 
You said you replaced the TL082's in an earlier post.

Where did you get them, and the other parts you've replaced?
I got the 6012's, 1495's, 201's from twisty wrist and the tl082's from mouser I believe
 
I got the 6012's, 1495's, 201's from twisty wrist and the tl082's from mouser I believe
I metered all pins on all chips in that section and compared them to the working boardset and pretty much got the exact reading. I scoped signals back to n/p3 and r3 Roms and got the same signals as well but I just noticed the 5v rail is down to 4.689volts. Don't know what that can be caused from but I bet that's a issue right?
 
Adjust the 5V to 5.10 on the main board, using the pot on the AR.

That won't fix your graphics issue though.

What are your +15 and -15 measuring, for the video section?
 
Adjust the 5V to 5.10 on the main board, using the pot on the AR.

That won't fix your graphics issue though.

What are your +15 and -15 measuring, for the video section?
+15.0
-15.2
 
Next step is to get your scope working, and get an image on it. This will let you probe the video section, to try to narrow things down.

Unplug the monitor for now, and leave it that way until further notice.

Put the scope in XY mode, put the probes on the XOUT and YOUT test points of the game board. Also, one of the probes will need its ground connection connected to any GND test point on the main board. Adjust the X and Y vertical settings until you can get an image on the scope that generally resembles what you see on the scope screen. If you need help with the scope, there are probably tutorials on youtube that can help you.

We could keep guessing here, but more data will make things easier. My guess is either one of the new chips you put in the video section is bad, or potentially there's a broken trace somewhere in the video section, possibly under one of the chips you socketed, or from someone else's past work.

But once you get your scope set up in XY mode on the XOUT/YOUT test points, we can give further instructions.
 
Thanks Andrew
You were right about the tl082's. I replaced the 4 and the words became clear. Now I just have some adjustments to make and hopefully everything will be done.
Thanks again for all your great help and support I appreciate it
 
Thanks Andrew
You were right about the tl082's. I replaced the 4 and the words became clear. Now I just have some adjustments to make and hopefully everything will be done.
Thanks again for all your great help and support I appreciate it

FYI, all four are not TL082's. Two are actually TL081's. It'll matter, as they're both op-amps, but the pinouts are different.

(EDIT: Strike that, I mistakenly thought we were talking about Asteroids. You're right.)

Happy to help.
 
FYI, all four are not TL082's. Two are actually TL081's. It'll matter, as they're both op-amps, but the pinouts are different.

(EDIT: Strike that, I mistakenly thought we were talking about Asteroids. You're right.)

Happy to help.
you're a good citizen. are our respective hiatuses over? lol
 
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