Possibilities:

- Fault in MIDI adapter/cable on the DIN side
- Dirt/oxidisation in MT32 MIDI socket, needs cleaning
- MIDI socket has dry solder joints internally, needs reflowing
- Something more serious internally (Hopefully not)

I popped the cover off to make sure there wasn't anything obvious. I'm sort of leaning towards cold solder joints which would require removing the board and reflowing. The jacks are slightly loose, but that could be normal. I may pop the board out and have a look.

I hope you can get it fixed! I haven't used my MT-32 in ages. I've been wanting to hook it up to a system for some retrogaming, but I kept putting it off. If they are prone to certain failures over time, I'd like to learn of them as well. Good luck.

digger wrote on 2023-12-17, 19:29:

I hope you can get it fixed! I haven't used my MT-32 in ages. I've been wanting to hook it up to a system for some retrogaming, but I kept putting it off. If they are prone to certain failures over time, I'd like to learn of them as well. Good luck.

I'm hoping I can fix it too! When I get a wild hair and can find my SB16 midi cable, I'll try hooking it up to my 486 to see what happens. I also have a midi keyboard kicking around that I can possibly connect to the adapter to test it out. We've got some extra troubleshooting that we can try!

I presume there's no native Windows game that will run on Windows 10 that can use the MT-32, hence you're presumably running DOSBox with MIDI passthrough?

Perhaps the Windows enumeration for devices has changed, and DOSBox is no longer sending to the correct MIDI interface?

edit: Whoops, obviously not, disregard.
> The USB-MIDI adapter shows activity whenever any of the games are started

I presume this setup has been known to work previously? I've met a bunch of cheap trash USB MIDI interfaces that don't work properly or at all with the MT-32.

SkyHawk wrote on 2023-12-23, 05:39:

I presume there's no native Windows game that will run on Windows 10 that can use the MT-32, hence you're presumably running DOS […]
Show full quote

I presume there's no native Windows game that will run on Windows 10 that can use the MT-32, hence you're presumably running DOSBox with MIDI passthrough?

Perhaps the Windows enumeration for devices has changed, and DOSBox is no longer sending to the correct MIDI interface?

edit: Whoops, obviously not, disregard.
> The USB-MIDI adapter shows activity whenever any of the games are started

I presume this setup has been known to work previously? I've met a bunch of cheap trash USB MIDI interfaces that don't work properly or at all with the MT-32.

Sorry, just saw this!

Yes, it was working previously. I disconnected it to move the PC, and when I reconnected it, it no longer works. Very strange how it stopped working. I don't think there's a hardware fault, as the MT-32 comes on and looks normal. It just doesn't receive any data.

I got munt working, but it's not the same. I'd prefer to use the real hardware if possible.

Just curious, do you have another device that you could attach on the thru of the mt-32. To check if the midi signal that comes in on the mt32 still goes through.
If not, it seems likely that the optocoupler inside the mt-32 is broken.

weedeewee wrote on 2024-02-26, 18:36:

Just curious, do you have another device that you could attach on the thru of the mt-32. To check if the midi signal that comes in on the mt32 still goes through.

Good suggestion- or hook up a MIDI keyboard directly to the MT-32's input. I've found the MT-32 to be a pretty well-made piece of equipment and would recommend not attempting any solder or reflow work until you're 100% sure it's actually faulty.

MattA wrote on 2024-02-26, 18:10:

Yes, it was working previously. I disconnected it to move the PC, and when I reconnected it, it no longer works. Very strange how it stopped working. I don't think there's a hardware fault, as the MT-32 comes on and looks normal. It just doesn't receive any data.

I got munt working, but it's not the same. I'd prefer to use the real hardware if possible.

Here's a really stupid question, but are you sure your USB MIDI interface is connected correctly? I've met several with the leads for MIDI IN and MIDI OUT marked in reverse - because they intend that the MIDI IN lead be plugged into MIDI IN on your device, not because it's the MIDI IN port on the interface. Bloody stupid if you ask me.

May I ask what your reservations are with MUNT? My MT-32 is now off my desk and packed into a box, because everything it can possibly do, MUNT can do better (and without taking up space on my desk).

I got back around to troubleshooting the problems with my MT-32. I've tried a new USB->Midi cable without success. Sometimes it starts trying to work and it'll start playing nonsense music without loading the patch banks, but then it'll stop working again. I think something is wrong with the unit itself. I'm not sure where to begin figuring out how to fix it, but it may have just bit the dust. I may pull the board and see if there's anything obvious, maybe on the connectors, but otherwise there isn't much I can do here.

Bummed.

MattA wrote on 2023-12-17, 05:17:

If anyone has bumped across this and has any ideas, please let me know. Otherwise, I see a lot of emulation in my future.

Oh, well. If you have a retro rig, you can still use an Raspberry w/ mt32-pi software in place of your real MT-32.
I do that, too and I'm quite happy with it. I do use my real MT-32 mainly for testing, if at all, not playing games.
The real MT-32 also serves as a license, essentially, so I can use a substitute without regrets.
I'm also a bit proud to be an MT-32 owner, of course. It's good to know there's a physical unit in the house, it helps to not to loose touch to reality in those days of emulation.

That being said, I believe the problem can be fixed, if there's any. Maybe it's something wrong with the MT-32's serial port.
A broken capacitor, broken diode, pull-up or pull-down transistor, some defect in the serial port UART..
The core electronics of the MT-32 is unlikely to be broken, I think. The control firmware should be okay if the display otherwise behaves normally.
So it can be fixed, eventually. Just takes time.

Btw, I do sometimes have issues with my USB MIDI cables, not sure why.
Their transmit LED (if any) sometimes don't blink when sending MIDI data from DOSBox.
It's a Linux system though, so there might ve other issues, too.

Also be careful, some cheap cables don't have opto-couplers or pull-ups/downs. Instead, they send 5v directly, which is bad.
Because MIDI via DIN port is a current-loop interface. There should always be opto-couplers.

http://midi.teragonaudio.com/tech/midispec/hardware.htm

On my mt32-pi build, I've implemented my own little interface with an opto-coupler, thus.

It's here: Re: Show us your custom Physical mt32-pi Builds

Re: Connecting Roland MT-32 to Modern PC?

That being said, MIDI and audio hats for Raspberry Pi should be available. Maybe even an mt32-pi hat.

Edit: I forgot to mention. I vaguely remember that the MT-32 and the normal MIDI devices have different channel assignments.
So better double-check this online. It might be possible that playing through a normal piano doesn't make a sound on MT-32.
Again, I merely vaguely remember something like that. I could be wrong, though.

I would definitely use a Roland USB MIDI cable or other non-cheap one (assuming you are using such a one currently).

Other most obvious troubleshoot which is mentioned already is MIDI Out cable needs to go into MIDI In. If it isn't, that would result in what you describe, MIDI cable seeing data (LED displaying) but not passing it on.

Spikey wrote on 2024-05-30, 15:08:

I would definitely use a Roland USB MIDI cable or other non-cheap one (assuming you are using such a one currently).

Other most obvious troubleshoot which is mentioned already is MIDI Out cable needs to go into MIDI In. If it isn't, that would result in what you describe, MIDI cable seeing data (LED displaying) but not passing it on.

+1

Some cables are being mislabeled, though. Here "MIDI Out" doesn't mean "This is MIDI output", but "Connects to MIDI Out port".
It's either a mistake, a reverse logic or the manufacturer underestimates the user, not sure. 🤷‍♂️