I spent my birthday breathing life back into DONOR-1.
This machine spent years on the road visiting several cities and requiring very little "field service" to keep going (always problems with the coin slot). However last year the screen went black and it became apparent that it was time for DONOR-1 to return to Gullickson Laboratories. Diagnosis didn't take long and the problem was that the ancient HP LCD monitor's backlight had finally bit the dust. Fortunately LCD's are cheap and plentiful in 2024 so the fix wasn't going to be expensive, but unfortunately finding a drop-in replacement wasn't an option.
After rummaging through my inventory I found a couple candidates and out of those I selected the newest display that was still small enough to fit into the control panel without having to move the controls. The next time I do this I'm going to start with a fresh sheet of plywood so I can design it around a newer, lighter LCD but for today this will work and should buy us a few more years at least.
To figure out exactly how much bigger I'd have to make the hole I needed to power-up the machine so I could see how much of the screen was actually in-use. This was also important just to make sure that the JAMMA board worked correctly with the new LCD and other details like having the LCD turn on when power is applied without having to press a button, etc.
Once the final position was selected it was time to cut. I wish there was a way to do a better job of this but the best option I have at my disposal is a jigsaw. Originally Jamie made a border for the screen that was used to hide my shame, and now that we have a larger 3D printer the plan is to print a frame for the larger LCD (I didn't get to that yet but I'll post updated pics when I do).
The LCD is held in place by four 3D printed "corners" which I assumed would need to be redesigned to work with the new panel. However a quick test revealed that they might just work as-is so I decided to give it a shot. Unfortunately two of them went missing at some point so I hunted-down the models and ran-off a new pair.
I also took this opportunity to upgrade the sound system. The JAMMA board includes a fairly powerful audio amplifier so all that is needed for sound is an external speaker. Originally I used a 4" "whatever I could find in the parts bin" affair. I had only planned to use this for testing but as we were crunched for time taking DONOR-1 to it's first assignment I zip-tied this speaker to the wiring harness and called it a night. I fully intended to address this when DONOR-1 came home after the first party but it never came home again until now, so...
The upgrade replaces this tinny thing with an exciter attached to the back wall of the cabinet. I've used these a number of times in Halloween props and they are a great way to add a lot of sound in small or unusual places. I'm not sure how high their fidelity is, but they are certainly up to the task of rendering the bleeps and bloops of the games DONOR-1 plays. With the original speaker the sound was ok, and loud enough to be heard even in a busy room but after the upgrade the machine is literally a blast. At 60% volume the cabinet shakes when bombs drop, adding a tactile dimension to the player's experience.
I have a list of additional improvements I'd like to make but I tried to stay focused on getting the machine operational by the end of the day so those things will have to wait until I have another free day to hack on this thing. For now it's back together and entirely playable and I'm looking forward to having it back in the lab so I can re-establish myself as the local champion of my favorite game.
