I just picked up a HUO TWD Pro a week before Xmas and it had the old 1.56 code so I just updated it to the 1.60 Cleland version - it is awesome.

The pin is in awesome shape, however, I have one minor issue with the Prison opto's. They don't always register during a game. They always work in test (rolling a ball) but sometimes (less than 20%) of the time a hit to the doors will not trigger the opto. I replaced the opto's with new ones and re-seated all the board connectors (back-box and opto board). I tried re-aligning them. The game does have a cliffy carbon protector around the prison magnet so is it possible that the ball deflects just high enough to not trigger the opto?

Usually, seems worse at the start of a game - but that might just be me imagining things. This game is hard enough as it is so hopefully someone can help me figure this out. Any ideas? Could it be an intermittent issue with the opto board? Anyone with a similar issue in the past?

Thanks everyone and Happy Zombie hunting.

Thanks guys. The cliffy was my suspicion as well as I knew that flashinstinct had recently installed the cliffy. ok, I am going to try the goo-gone method tomorrow (and hold my breath).

ok, so I wasn't feeling confident at going at the mint playfield with goo-gone.

So I decided to see if I could lift the opto's up a little higher from the playfield. Turns out you can. I took off the plastics over the opto's and then figured out how to add 2 washers to each of the four bolts (8 washers total) holding the opto ball-guards in place. The right side was easiest (as you can get at everything from the topside of the playfield). The left side required removing the two nuts from beneath the playfield. I also added two extra washers underneath the left side plastic so as to not stress the plastic (as the ball guide was now a little higher and touched the plastic).

It took about 30 minutes or so to figure everything out and do the work.

This seems to have resolved it for the most part. I perhaps have about 5% non-registering now (maybe less).

I recommend that you get the plastic protectors for those two plastics as they are pretty thin and are in high impact areas. Mine has them.

I also got around to hook-up my Polk sub-woofer too! Awesome (but not sure my wife agrees).

Thanks for the help guys.

ok, just to clue up this thread. So after adjusting everything with washers (see above), swapping the opto-board and optos I was still getting about 10% rejects from the prison optos not registering. So I finally removed the carbon cliffy - bingo 100% of the time it registers now (after 40 games). I was really hoping to resolve the issue without removing the cliffy as I was afraid I might damage the playfield.

My magnet was 100% level. I can't believe that very thin carbon cliffy was causing such playability issues on my particular game - but it was.

Here is how I went about removing the cliffy (for future reference for those that might need to). I simply lifted the front edge a little with a box cutter (being very careful) and worked a piece of dental-floss under-neath. Once the dental floss was worked under the front 20% I was able to slowly saw underneath until it was completely loose. Then I simply used goo-be-gone to remove the glue residue. (As others have stated: Do NOT use GOOF OFF!) It was pretty painless!

This game plays so much better now - it was amazing how frustrating it was to have the optos not register so often and then lose your ball. It felt like I was becoming Dead Inside.

Cheers.