Tempest X Out Issues....

Pinball Wizard

Well-known member
Joined
Sep 20, 2010
Messages
3,084
Reaction score
407
Location
Baltimore, Maryland
I am moving this from the monitor repair thread as I found out that this is a board issue. My X out only has 40 mV AC coming from it. Y out is about 3.6 V AC. So that means my X side is dead. What do I need to do to fix it?
 
Fixed.. Just move my website the other day, and there were a few broken sections..

That's why I have a web guy.. I do board repairs. :)
 
It wil probably have to wait until Wednesday to test, but I will get to it soon, I miss playing Tempest. Question, if my scope is 20mhz, am I not going to be able to test properly?
 
Well, it appears that the scope readings start to match up at b11 pin 10. Before that the signal seems like garbage, but then again my scope doesn't seem to ever fully match any thing, so I have to question the integrity of my scope. So if it is accurate, what does this mean?
 
I assume when you say before you are meaning closer to the X out.

Without seeing exactly what you are seeing, I would assume the TL082 @A11

Those are cheap and you can get them at Radio shack.

The next chip would be the LF13201 you can replace that with a DG201

I believe you shouldn't see anything @ B11 pin 10. If you are, then you definitely have a problem with B11, and or A11
 
Get an oscope and see where the signal dies. Could be and op amp, switch, or mc1495 in the x side. You'll need to follow the schematic. Wave forms can be found on my website.

WWW.txvectorarcade.com

Thanks! Those waveforms were exactly what I needed! I had no Y out tracked to mc1495 then it mostly worked pic half off the screen.

Ended up also having a bad Y - center pot. The pot worked fine but was only 8.4k not 10k so I robbed another board got one that measured 9.6k and the game works great! (gonna get a new set of pots though for good measure)

Thanks for the great resource!
 
Glad they were able to help.


Thanks! Those waveforms were exactly what I needed! I had no Y out tracked to mc1495 then it mostly worked pic half off the screen.

Ended up also having a bad Y - center pot. The pot worked fine but was only 8.4k not 10k so I robbed another board got one that measured 9.6k and the game works great! (gonna get a new set of pots though for good measure)

Thanks for the great resource!
 
Back
Top Bottom