Are the original displays programmed in a “do this with pixel ,3,3” that is uniform at some level? Or are the displays more like a terminal? Is there a way to unify these things?
Jazzcat + Ebay sell expensive replacements, but they are actually just cheap LCD displays with the driver circuit bypassed (since the MPC/sampler has a discreet IC) and an epoxy blob to prevent copycat work.
I need to dig up the wiring diagram, but the gist was from an EEVBlog forum post and only took an evening to reverse engineer.
This interfaces with the CPU's bus and produces very low-level clock & data signals to the LCD panel (CL1/CL2/FLM/MB/D1) - basically a stream of pixels along with synchronization pulses.
Nowadays most "graphic LCD" modules will incorporate a similar chip on-board, so that they can present a simple 8-bit parallel interface.
Capturing + translating the signal would be tricky - it's not _terribly_ fast (240x64x60Hz) but there's no flow-control or error-correction, basically low-resolution video capture
Yes, they were professional equipment. Yes some have unique workflows or analog stages that make them interesting.
That said, having fixed a lot of audio equipment in my life, there are a lot of off-the shelf parts for things and a lot of close equivalents.
For instance, the display in the Roland XP10 keyboard uses a pretty standard, segmented LCD controller. All I had to do was figure out how to connect the ribbon cable to some specific pins on the controller, set a color (because the controller I added was now backlit, which is an upgrade).
And then you discover that the plastic on the keys has some deformation over the course of 40 years, so everything is sticky and you need to get a dremal and rework every key.
In any case, I found that with these kinds of long term projects, your are often better off "going back to school":
get an arduino and a couple of different controllers that seem similar to the one in the devices you're interested in,
build some displays that are similar in topology to those displays
find the schematics for devices-of-interest
build some similar displays until you understand how the displays are working in those devices.
After you've done a little work like that, you can start to look at schematics and datasheets and figure out what kinds of parts that you're needing to implement the display.
IME, that's a couple of hours a week for a couple of months, but after that you're in a place where you can do what you'd like as far as avoiding $250 drop-in replacements.
Unfortunately, with your s3000, it may be the case that there is a different issue- the memory is non-functional (about 20 years ago, I had an s2000 go wonky cause the diodes in the cheap simm I put in it blew up).
Anyhow, if you're a software guy, then you know how to learn stuff- you're gonna have to give yourself a little hardware school before you can do what you'd like to do.
I found it fun, but in retrospect my time would have maybe been better spent making music or making money so I could afford time to make music.
You can duplicate that effort. You can buy one, figure out what display they are using, and order more. You can order the bezel and duplicate it on a laser cutter. Is it worth it?
* Find an equivalent LCD matrix. This is probably not that hard. This display seems like a generic part and LCD matrix displays haven't changed much over time.
* Fix the backlight. That would mean taking the display apart and probably resoldering some LEDs, assuming that it's the LEDs and not, say, a capacitor that is causing the brightness to diminish.
Going beyond these options, you'd be getting into decoding the commands to the LCD driver chip and displaying those somehow, which will be custom hardware development.
In rough order of difficulty/complexity:
Simply remove the module, wipe down the connections with alcohol, reassemble. If there's a 'zebra strip', gently peel it off, clean both ends, reassemble. If you see improvement, repeat with care until all segments are alive again.
Replace the backlight. Depends on the exact module, but sometimes they're just simple LEDs that can be replaced.
Ensure the polarizing filters still work. You'll need to research LCD polarizing, it's more complicated than I care to explain in a HN comment. They can degrade and sometimes need replacing.
Beyond this, you're looking at an electrical fault or the display is just dead. You'd have to start probing the display driver to examine the signals. A good starting place is to replace all the electrolytic capacitors.
Barring that, you likely have a bad display module. Sometimes you can test them by connecting some pins to ground and just touching other pins with your finger. The static electricity in your body can be enough to flip segments on
Check eBay - I got mine for much cheaper than MPC Stuff from a UK seller
Can you tell if the pixels are correct and there’s just no light? If so, the LED backlight replacements mentioned would be the answer.
There’s videos on YouTube with guides on using old iPhone screens to illuminate the old screens.
Also these displays are still available, but usually come with driver ic’s blobbed on. You can probably just bypass the blob or even mount the lcd module on the old board. (They usually just are mechanically attached ). Buy a couple of cheap character displays of the same size to practice tearing them apart. You should be able to find them around 5 dollars for the 2 line displays.
Give yourself time to learn electronics and how to repair instruments. Maybe it will be your new hobby and you will buy an oscilloscope. Maybe it won't. Good luck.
As I understand it, you just want to be able to control the device. Maybe keep the display as is, intercept the signals and forward them (wirelessly) to an external device for display?
if you are concerned about $200 for a replacement kit you should probably sell them to someone else