Atari 2600 Mylar Switch

[ninoy1995]

For the Atari 2600 Jr., when you open up the console, what you see underneath the "Select" and "Reset" switches is a thin plastic with circuit traces. I beleive they call this the mylar switch.

 

My question is. What causes that "burn" or the black spot on the circuit trace on the mylar switch on old Atari 2600 Jr.?

 

Appreciate your inputs.

 

Thanks!

[+5-11under]

I've never looked at this on a 2600 Jr. specifically, but I'm guessing it's corrosion (or burning from high current, although I find that hard to believe). Either way, some gentle scrubbing with a pink eraser should help.

[A.J. Franzman]

Probably simple tarnish. Silver is a main ingredient of printed conductor "inks" in membrane switches because of its high conductivity, plus the interesting property that unlike other metals' oxides, silver oxide is nearly as conductive as pure silver. There's no need to clean it off; doing so only adds a high risk of damaging the part. If it works, don't mess with it. If the switches work sometimes but are unreliable, you might try modifying them as I described here.

Edited November 25, 2010 by A.J. Franzman

[+5-11under]

Sounds good. I guess if it ain't broke, don't fix it.

[zylon]

When it's broken is usually the best time.

[ninoy1995]

Thank you all for your inputs!

 

Cheers!