Hello Everyone!

YES I am perplexed. I have a TZ with no credit dots. The ONLY issue is the second button on the service switch (Volume down) does not register. The down volume switch is on the Orange Blue-wiring which as far as I can tell is a dedicated wire. The machine has a brand new Rottendog CPU board.

I REPLACED the entire service bank including adding in the ground line but I get the exact same results. All other switches on the service bank worked before and after the replacement. I have continuity between the service switch and the Coin door interface board and between the board and the connector to the new CPU board. I have also jumped this connector and it registers continuity but fails to activate the switch. In SWITCH TEST Mode the button does not register (Volume up registers fine). I am assuming the problem is upstream of the CPU board since there are no other errors. Would the issue be somewhere on the Power Board? I am not the best at reading schematics but I believe that is where it goes next. IS there a dedicated transistor or other component on one of the other boards? Feel free to offer suggestions!

When you say jump the two pins do you mean the pin for the orange-blue and ground? If not what other pin? Also with connector off or on? THANKS!

No its a brand new CPU with a remote battery pack.

Thanks Lloyd! Will test and report back!

Lloyd - Did this and found that the issue was with the board. I traced up to the Diode and found the banded side was not engaging the switch but the unbanded was. With all of the other switches either side of the Diode once grounded would engage the switch. So I swapped out the DIODE (Had some in stock thankfully) and BINGO the switch works fine now! Thanks as always for your advice and support of everyone in Pinball!