+/- sense?

It can differ slightly depending on the game/manufacturer. A lot of Bally schematice lists +/- sense lines.....some arn't used....a lot are tied directly to 5VDC (for + sense) and ground (for - sense). On Atari games....it's a sorta feedback circuit for the 5VDC and ground lines. In this situation, they are not tied directly to their respective 5VDC and ground lines. This is where you heas a lot about the "sense mod". In essence, the "sense mod" is nothing more than shorting out the sense circuit. Some people are for it....some are against it. I'm against it :) I think a lot of people for it.....really don't understand it....they're just doing what they read online, which that person (subsequently) read online, which that person (subsequently) read online....etc. The birth of an urban legend :)

Edward
 
I think in this case he may be asking because of his 720 which is a bit different then other Atari games. For 720, the sense lines went to a switching power supply which is probably long gone or at least should be. If that is the case, I'd say run +5 to +sense and GND to -sense.

Elutz, what do you think about that situation?
 
I think in this case he may be asking because of his 720 which is a bit different then other Atari games. For 720, the sense lines went to a switching power supply which is probably long gone or at least should be. If that is the case, I'd say run +5 to +sense and GND to -sense.

Elutz, what do you think about that situation?

I just pulled the schematics......they're tied together on the motherboard. So, yeah....+ to 5VDC.....- to ground.

Edward
 
I'm for it. :)

I'm sorta neutral :)
My problem.....so many people tell other people to do it....without any idea what the REAL problem is. It's treated like a fix all.....when the actual problem is the shot edge connector (as I know you know :) )....and a sense mod doesn't fix that (it just masks a future, and potentially more severe, problem).

Edward
 
I'm sorta neutral :)
My problem.....so many people tell other people to do it....without any idea what the REAL problem is. It's treated like a fix all.....when the actual problem is the shot edge connector (as I know you know :) )....and a sense mod doesn't fix that (it just masks a future, and potentially more severe, problem).

Edward

True dat. Cleaning/replacing the edge connectors is a must no matter what you do. I like the sense mod too not only because it might save your AR from getting a nice little burn hole, but when it flakes out you know it's time to clean the edge connectors too.
 
I don't think a lot of people change the edge connectors which is the problem. They'd rather buy an old harness and hope that works instead of fixing the on they have.
 
OK,

Since it really hasn't been explained... +/- sense are lines that the power supply uses to determine if the output of the power supply needs to go up or down to maintain proper power levels on the board. As the edge connections deteriorate, the power supply output increases to try and maintain the proper 5v levels on the board which eventually cascades into a burnt edge connector.

OOPS.
 
I think in this case he may be asking because of his 720 which is a bit different then other Atari games. For 720, the sense lines went to a switching power supply which is probably long gone or at least should be. If that is the case, I'd say run +5 to +sense and GND to -sense.

Elutz, what do you think about that situation?

i am talkign about my 720... those lines ARE NOT hooked up.. and thats the way i got it.. The game runs fine without it, question is, do i need to hook them up or leave them alone??
 
i am talkign about my 720... those lines ARE NOT hooked up.. and thats the way i got it.. The game runs fine without it, question is, do i need to hook them up or leave them alone??

Since they are tied directly to ground and 5VDC on the motherboard.....it ultimately doesn't matter. According to the schematics.....the original power supply did have a sense circuit. For whatever reason, Atari chose to not use it in the design of the 720° motherboard. So.....electronically speaking, it's irrelevant. Now, I would tie them to the ground lugs (- sense) and the 5VDC lugs (+ sense).....just so I didn't have loose wires in the cabinet( plus, it would beef up the ground/5VDC rails). I'd also guess, this is how it was done originally from the factory.

Edward
 
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