Robotron Cocktail Controls

Newfie

Active member
Joined
Jun 6, 2009
Messages
426
Reaction score
84
Location
Fergus, Ontario
So I managed to get the screen to flip for cocktail play (W1 on the widget board), but the player 2 controls don't work. The player 1 controls work when it's player 2's turn (in reverse of course), but P2 controls do nothing. This PCB used to be in an upright. Is there something else I need to do?

Shawn
 
OK so I checked all the wiring for the P2 controls, looks good right down to the interface board. Am I missing something obvious? Is there something in the settings I need to change? Does only certain board sets or ROM sets support cocktail mode?

Any help would be appreciated.
 
those all should. the only ones that couldn't were the early revision Defenders were the green label roms. there should be additional jumpers to change on the rom board if I recall.
 
Manual has very little info in it. I couldn't even find a drawing set for the cocktail to tell me which pins were for which controls.

I will swap out the old ROM board with the current one and see if that does anything.
 
it's possible that the Interface board is bad. Make sure R1 on the interface board is present. The cabinet drawing set shows the cocktail controls. Pin 17 on the 6821 PIA should be high if R1 is good, W1 pulls the pin low to denote upright.

Not sure if you need a different version of the ROM code for cocktail or not. The instruction manual might show.

Good Luck.
 
So I just noticed something else. The Player 1 start button doesn't work. I checked continuity from the leaf tabs to the interconnect board, looks fine for ground and the other tab. Then swapped in my upright setup (MPU, rom board, and I/o board) and the P1 start still doesn't work. Very odd. The Player 1 start button worked for my upright, so I don't think the boards are a problem. Could it somehow be a wiring issue even though there doesn't seem to be a connectivity issue?
 
More research on this leads me to look into the ground straps. Are they all supposed to be connected somehow? The one coming from the P2 control panel goes underneath the coin box, but is not connected to anything. The one coming from the coin door is screwed into a metal part of the coin door, but not connected to anything. There is another piece of ground strap inside the cabinet that looks like it could be connected to the ground strap from the coin door, but it isn't. Should I be looking into this?

I have a Bubbles game that works, are the interface boards the same?

Thanks.
 
The grounds are very important. And yes, the interface boards are the same.
 
Just to circle back on this, i replaced the I/O board and still had the same issue. Looked for some pics on the 'net to see if I could see how all the ground straps were connected, found a Defender cocktail pic that helped me. (Ground strap from coin door connects in two places, one to the main ground strap that connects to the speaker assembly, the other runs under the coin box/lid and connects to the ground strap from the Player 2 control panel.)

Thanks for the help.
 
Back
Top Bottom