Support and discussion for all of Akai’s modern standalone MPCs including the MPC X / X SE, MPC Live 1, 2 & 3, MPC One / One+, MPC Key 37/61.
By Sumilumilux Wed Apr 22, 2026 12:39 pm
Hi all,

I’ve had an mpc x shelved for many years meaning to return to fix it. I can’t afford to spend hundreds on replacement circuit boards so it has to be a repair but before I attempt that I thought I’d ask here for advice here from anyone familiar with re serialisation. Mine says ‘invalid serial number’ also what may be causing the control surface to show <Unknown>

Is this controller unknown problem a known hardware fault and if so it’s likely a simple connection issue as some cables were yanked when it was opened by a previous owner. The machine had Wi-Fi problems and this I discovered was down to a torn off Wi-Fi cable.

Is there a test mode that is able to identify communication problems between circuit boards and their control chips

Thanks
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By Ultros Wed Apr 22, 2026 7:44 pm
Sumilumilux wrote:Hi all,

I’ve had an mpc x shelved for many years meaning to return to fix it. I can’t afford to spend hundreds on replacement circuit boards so it has to be a repair but before I attempt that I thought I’d ask here for advice here from anyone familiar with re serialisation. Mine says ‘invalid serial number’ also what may be causing the control surface to show <Unknown>

Is this controller unknown problem a known hardware fault and if so it’s likely a simple connection issue as some cables were yanked when it was opened by a previous owner. The machine had Wi-Fi problems and this I discovered was down to a torn off Wi-Fi cable.

Is there a test mode that is able to identify communication problems between circuit boards and their control chips

Thanks


The way to make this easy is to roll back to an older rom 2.xx rom and get into the diagnostic mode. i forget which buttons you have to hold down while powering it on. search for that.. but after you do you can reserialize it and run all the input interface diagnostics on the unit to make sure the input is operating properly.

Or if you can get ssh going, you can just toggle a script from /usr/bin to reserialize iirc its /usr/bin/az01-midisomething.
By Sumilumilux Wed May 06, 2026 1:25 pm
Ultras you are very knowledgeable on reflash. I will search and find the key combo for the maintinance mode. As a forum regular have you helped anyone solve the no controller issue which I suspect is a software problem. Also seems v2.10 firmware had issues with hardware disappearing.. Are you able to describe the process to force an update via jtag and also which version to update to before the big v3 change. I’m familiar with Linux and have a art programming lead somewhere
By dustyslices Thu May 07, 2026 4:51 am
Most likely it's a bad flash of an stm32 chip. Don't quote me on that but serial is carried by a microcontroller on audio/midi card, after boot it's being extracted and written down into a filesystem (don't remember exactly where). If I recall correctly it is exact same chip as those cheapo amazon "black pills" - stm32f4xx.