I seem to be procrastinating the Gyruss multi-game high score save kit project given all the soldering required, but that is proving productive in other ways. For example, yesterday I decided to swap out monitor chassis* for both Stargate and Phoenix. There was a cold solder joint in Stargate that resulted in the red color not working after the game warms up. This was annoying me, and when I was in the US back in November I picked up a few extra chassis, in particular the Wells Gardner K4900 series given 4 of my games have some variation of that chassis. The K4900 has several versions distinguished by the number of adjustment controls (known as pots) they have: so there are 3-pot, 4-pot, and 5-pot models. I have a 3-pot and a 4-pot K4900 chassis for 19″ monitors (which all my games in Italy have currently), and the 3-pot was what I needed for Stargate.
I was a bit nervous with this one given I dropped the chassis in the parking lot of Reclaim Arcade when brining it to my car, but apart from a corner chipping, the chassis worked beautifully, and Stargate is no longer losing the red color after warming up. YEAH! Overall this was easy, but the one thing about the K4900 3-pot chassis is the vertical positioning is controlled by a jumper cable that gives you 3 different options, I had to move this to the left-most connector to position the screen perfectly.
After that I spent about 30 minutes chasing my tail finding the volume control on Stargate cabinet given it was pretty loud. After some research I realized it was right in front of me the whole time.
For Williams games like Joust, Defender, Robotron, and Stargate they have a separate sound card that has a separate volume pot that is actually not on the board, but connected via a wire to be more convenient for coin door access. It’s not like other volume control pots on other games that are usually on the game board.
The other chassis swap was for Phoenix, which is using a 4-pot K4900. I knew this chassis was solid because I watched the Arcade Buffett service and test it and I did not drop it in the parking lot 🙂 The swap out was pretty easy and the adjustments were minimal It was good to have this one swapped out because the right side of the screen was compressing given the chassis needed a cap kit, and it would only start to correct after warming up for 30 minutes.
This also means I have 3 cap kits to do: these two monitors and the G07 I replaced on Astro Invaders earlier this fall, so once I have the home arcade dialed-in—which is getting really close now—I can turn towards practicing my soldering on cap kits and building up some reserve chassis.
*A monitor chassis is the unit that interfaces between the game board and the CRT tube. It essentially converts the code to interactive light via some kind of amazing 3-color beam alchemy.