Since yesterday I am a proud owner of an almost mint STTNG but it has one technical problem.
In video game mode the left flipper does not work. During normal play it works fine. What should I look for to fix that?

In the forum there were only two other topics about that issue but one was unrelated (Gottlieb) and the other one was not resolved.

Any hint is welcome.

I did blow some air in it and re-soldered it, now it almost works. The 4th dot on the right from the test menu blinks but I think there need to be 4 squares. So I assume it is really broken.

The current receiver and transmitter is together as one part, could I just get a set like this to replace it? http://www.pinballlife.com/index.php?p=product&id=167

STTNG.JPG

A full flipper board coast about $35 and is not optical but mechanical. The replacement opto component is the Fairchild Semiconductor QVE11233 and cost just about $1.25 but the minimum order quantity is 50 pcs.

Because I had nothing to loose, I took the board out again and now really cleaned it well with hot soapy water, used canned air to blow dry the lenses and let it dry another day. Now it works perfectly!!!

I found on another forum an explanation for this, some plastics sweat, after a while an oily substance comes on the top and dust sticks to it so they become less transparent. With soap you can wash it away.

I was referring to this Universal WPC Flipper Opto Board from MAD amusements: http://67.225.159.30/product.php?id_product=794

But thanks for the tips, a good clean helps.