err :(

[Zsoli]

What?
c001,c02,c003...
err1
err2
err3

[DesmoBob]

Looks like it developed a case of amnesia due to a dead battery. Unfortunately, the battery is soldered in place. You could unsolder it, and then solder in a new one. But if you're going to do that anyway, it may be worthwhile to do the battery mod:
http://adadepot.com/mods/ADA_MP-1_Battery_Mod.pdf
Note in the pics, they replaced it with a CR2032 battery and corresponding clip.
The OE battery is BR2325, and the clip on Mouser is part # 534-104.

BTW, dead battery probably also means your patches have been erased.

[MarshallJMP]

yep replacing the battery will solve your problem.

[rnolan]

Hopefully you've backed up your patches (or written them down), or it's start again (not always a bad thing though). It seems there's a spate of MP1 battery failures lately, the year is upon us.

[Zsoli]

Battery good: 3.12 V :(

[rnolan]

Mmm well good about the battery, not good about the errors, maybe it's the RAM chip ?

[MarshallJMP]

Measure on pin 28 of the RAM chip (6264) located next to the eprom (it has the same size),you should have around 2.5V with the unit off.