Exchange tips and tricks for the Akai MPC4000
By radialMelt Sat Aug 10, 2019 4:56 pm
Hey all,

Registered to post my experience in the event it helps someone else in the future.

I recently received an MPC 4k that was sent to me via international post. Prior to shipping, the unit was working 100% fine. When it arrived at my door, I fired it up and was met with a display failure. The screen would power up (backlight fine, contrast knob fine) but nothing would be displayed. Sometimes it would be full white, sometimes nothing, sometimes weird lines, or sometimes a "blob" that emanated from the backlight.

I did all the basic troubleshooting steps: reseat ram, reseat connectors, inspect LCD ribbon cable, reseat LCD ribbon cable, etc. Nothing helped.

As it turns out, by following the signal back from the LCD and across the various PC boards inside, I managed to pinpoint the problem to a faulty connection between two of the PC boards - a connection that is responsible for, amongst other things, passing LCD data. If you look inside you will see that the main IO board (that has the LCD ribbon connector) connects to another IO daughterboard via a multipin connector labelled J8. The two boards are stacked - one sits on top of the other. My theory is that in shipping, the unit was jostled enough to cause a malfunction with this connection. After completely disassembling the MPC, i.e., removing all the PCBs, cleaning the contacts, and reassembling tightly, my LCD came back to life. And it didn't cost me a cent. I was about to order one of those overpriced screen replacements too.

Anyway, hopefully this helps someone in the future!
User avatar
By JUKE 179r Sun Aug 11, 2019 7:36 am
Thanks for this.
I still need to tear into my 4000 and fix the screen and failed tact switches.