Roland MDX-500 questions

Hello there, I know I'm new around these parts but I have a question that I hope someone somewhere can answer.

We recently moved our machine shop to a new location. We lost the "Key connector" for our MDX-500. Roland DGA confirms it's a discontinued part and no longer available. Yes I've contacted probably 8 authorized service places across the US and one in the middle east. The one in the middle east is pretty sketchy and I'm not sure I'm willing to risk $250 on a part that they still have to source themselves.

Our shop is happy to purchase the part and or manuals, but no one seems to have them or want to sell em.

Does anyone have a "key connector" that they could analyze for me?

Does anyone have a spare?

Finally the question that no service technician likes to hear... Can anyone find the schematics and or repair notes or manuals for this machine? I know the 600 and 650a were similar. If I could find a copy of those they might work too.

Help?

Thanks for the reply @tommylight! As soon as we get this up and running we plan on trying LinuxCNC

Unfortunately the system won't accept any input without the key connector inserted into EXT.1. On that same document link, check out page 14 in the manual, or page 16 of the pdf itself.

"Key connector
* The machine does not run unless
this is inserted."

It is an 8pin Mini Din connector with either DRM on it for the main system or an interlock between other safety switches. Without it the machine is in "emergency stop"

The message on the display is "EMERGENCY STOP EXT1 IS NOT CONNECT"

The users manual states that without this key connected the machine will accept no input and will not function at all.

We were going to dump files directly to the LPT port, which worked before we lost the key, but we're kinda stuck now

I grabbed the multimeter yesterday and started checking pins, voltages and states. This is a little different than I'm used to. One pin is 24VDC, a couple pins are 9VDC and one pin looks like there is something bouncing around around 300mv so I might suspect its a data line. I can get the scope out and take a look at it.

Is there any way to get schematics for this machine? I asked Roland and they basically just said "no", but were very nice about it! I'm not surprised as the machine is no longer supported.

I have schematics!

The PDF contains no dongle pinout, however I think it should give me a head start on making the dongle (key?)

I'll update this thread with what I find to make sure the loop is closed and anyone searching can find this. Eventually we'll be using linuxcnc but not quite yet...

Huge thanks to Nick Gill on the facebook group:

www.facebook.com/groups/902876403145632

shorting these pins on ext.1 works. The mill is now functional!

I hope someone finds this helpful in the future.

Cheers!

Quick word of warning though - DO NOT *randomly* connect other pins to test this connector. There is one pin that connects directly to a Roland ASIC and there is no protection on that circuit. It is highly likely that damage could occur.

Use this method with caution and be careful to ONLY connect those two pins together.

Sorry for the necropost, but I recently inherited a nonfunctional MDX500, and want to gut it and replace the electronics. Any chance you'd be able to to share the schematics? I don't think this thing has ever received maintenance in its 20 years of life, and I'd like to get it up to snuff.

Thanks!