Korg M1 unresponsive with INT and PROG lights

[ckrallman]

I dusted off a Korg M1 that had been in storage for many years, with some of those years in a seaside home. To my surprise, it powered right up. The INT and PROG lights were illuminated and it displayed, "KORG Music Workstation M1 #24". Unfortunately, beyond that, it's completely unresponsive. There are no sticking keys or buttons. It emits no sound and, regardless of what button(s) I press, the display remains unchanged.

I opened the case and found the inside of the unit to be pristine. There was no corrosion or even dust. In fact, it looked as-new. I checked that all connectors were properly seated (they were) and replaced the backup battery. I saw no visible damage to any of the PCB's, components, or cables.

I put it back together after changing the battery and checking the connectors and got the same result. Does anyone have any idea what I should try next?

[desmond]

How to Initialize (reset), and preload on the Korg M1:-

Initialization: Hold Int, Card and Combi while turning it on.
Preload: Card Load (MPC00P)
ROM Check: Hold INT while turning it on.

[ckrallman]

How to Initialize (reset), and preload on the Korg M1:-

Initialization: Hold Int, Card and Combi while turning it on.
Preload: Card Load (MPC00P)
ROM Check: Hold INT while turning it on.

Thanks, Desmond. I tried these button combos, but without effect.

[madtheory]

http://forum.vintagesynth.com/viewtopic.php?t=109664

[ckrallman]

@madtheory - I saw that thread, but the actions required are a bit above my pay grade. I was hoping, perhaps unrealistically, for a fix that didn't require a meter and a board component change.

[desmond]

If it can't be resurrected with a reset, then it's faulty for some reason, which will require some expertise (or a tech) to open it up and look to determine what the problem is, and thus how to fix it.

Whether the value of the synth is worth sending it to a tech is debatable, so I guess it really depends how confident are you in your electrical troubleshooting skills?

[ckrallman]

Thanks, Desmond. The answer to your question is I'm not confident at all and the keyboard is currently in the Virgin Islands, so I guess that seals its fate!

[dbtx]

Hello, here is a shot in the dark: it seems the system freezes solid during its initialization. IMO the low-hanging fruit here is the OS EPROMs, IC32 and IC23.
Are they socketed as usual & thus removable? if so, did you try reseating those as well? If that didn't change anything, it's also remotely possible that some bit rot occurred over time, corrupting the code-- since the chips are erasable. You could try replacing them, as they're on eBay for relatively little (around $20 US).

[ckrallman]

Thanks, DBTX! The eproms are seated well in their sockets, but I'll look into ordering new ones.