Duotron 2: Fixing Issues, Updating Parts & Learning

Not a big post, but just an update to the ongoing Pinball Project.

First, I've worked through two fairly significant technical issues:

1. Specials Light not lighting, special not awarded
   This turned out to be a wiring issue (still not found, but fixed via a jumper from the head to the table, so probably in the Jones Plug / Receptacle used when one takes the game apart)
   
2. Two Player not playing all ballsTurned out to be some mis-adjusted contacts on the Scoring Motor, which spins some cams around for sequencing and timing. It's a delicate  behemoth (multiple cams and switch positions, driving 11 individual switches) and I suspect I'll get to know it better over time, as it seems to be the one place that gets the most wear and is most likely to malfunction. 

I've also replaced all the rubbers / rings, including the bumper at the top of the game, the springs and rubber tip of the plunger. One oddity - the captive ball in the center was delivered with multiple rings, with the possibility of ball-ball contact (a nice satisfying "click") - but the ring kit had a single 4" ring (see below) which seems to be the official way (based on the image on an old Gottlieb flyer).

After playing it both ways, I put the modified version back - the 4" ring made it way too springy and easy to score (the captive ball would tend to bounce back and forth on a single hit). The pins (green arrows in the image) seem like they may have been added to keep the ball captive without the 4" ring.

I also purchased replacement bulbs (both incandescent and LED) - ended up replacing the under-table (inserts and features) and back-glass lamps (indicators, score reels) with LEDs (cooler, less likely to dim / flicker, minimal aesthetic impact) - leaving the above table lamps incandescent (a nicer yellowish glow to 'em, even the frosted warm white LEDs seem to white).

I also replaced the pop bumper caps (new ones in the image above) - the old ones were quite faded. And I've slowly stocked up on infrastructure - ordering and receiving jumpers, multimeter clip-on probes, a couple of rechargeable work-lights (super bright and super handy, with magnetic base, retractable hook, and swivel lamps), some fine grit sandpaper and small files for contacts.

So...basically having a lot of fun with the beast, both playing pinball and working on it. I've pretty much scored every way possible (finally got an actual Special replay this evening while playing, as opposed to testing). Replays via points are easier to come by, as are end of game matches.