Sequential Multitrak bug - glide and display off!?

[syevad]

My newly bought Multitrak is randomly stopping playing and start with a very long glide sound while all leds and digital program number display goes off (wtf?!).
I thought it was the battery - in fact after turning it off and on again the tuning function starts (count from 1 to 6) but the presets are still there (a full battery drain should had wiped the presets).
So...is this a known bug?
btw - I've found out the firmware is 2.1 and is older and not the official version 2.2 which I've ordered online - arriving soon and hopefully the thing is going to behave.

[syevad]

it seems there are more than one bug in my Multitrak - some parameters's range don't reach the very top value - e.g. filter CutOff maximum should be 2.7 but mine reach only 2.2kHz - I wonder if this is a graphic/display issue only or the actual fiter cutoff is limited somehow.
Any help out there?

[meatballfulton]

A slightly low cutoff frequency can be just a trimmer issue. Get the service manual and read all the calibration instructions.

[syevad]

A slightly low cutoff frequency can be just a trimmer issue. Get the service manual and read all the calibration instructions.

I guess you are in the right track...the manual doesn't mention specifically a link between a trimmer and some parameters out of range - but it make sense to me. I remember discovering how to change the speed of tape recorders by adjusting a trimmer with a screwdriver. I might just experiment by simply adjust the trimmer and see if the range of these parameters go as far as they should - if it doesn't work, it's just a question of undo the operation and find out another solution.
Before trying this experiment I'll do a bit more research (one thing is to mess about with an common tape recorder - but the Multitrak is becoming a rare beast these days).