My Buck Rogers machine (that I acquired recently) has a vari-target. Depending on the position of the vari target (base, 1-2-3-4-5-return to base), different points are awarded. The current position of the vari target is of course "visible", but also shown throught a series of lights (see attached picture). The light bulbs are just fine, when I put the machine in "lamp test" mode, they all work.

varitarget (resized).jpg

During a game, only positions base, 1-2 and "return to base" light up. So something's wrong with 3-4-5.

I checked the vari-target connections below the plafield using the multimeter diode mode, and after some cleaning they all consistently show connectivity between "in" and "out" connectivity (through the fingers of the vari-target).

Reading the switch matrix, the "test button" and "vari target rollover" on the same strobes all consistenly work, but not the vari-target 3-4-5.

switchmatrix (resized).png

There is a transistor involved (TIP-115) but not specifically for the 3-4-5 I think, and my DMM measurements seems to indicate it's working..

tip (resized).png

It seems the CPU is not receiving the events from the vari target, but why?

Any ideas?

It seems it is an issue with the CPU board, specifically for my Buck Rogers (I have one of those fancy all-in-one boards from flippp.fr).
I contacted them, the issue/bug was already fixed, but I have an older revision so I need to send my board back and they will upgrade it on their expense.

Great customer support!