I’ve had one of my Oberheim Matrix 1000 units apart today, initially I’d put it aside because it exhibited an audio hum (but now it doesn’t)

However, it’s taking ages to power up into a usable situation, it has the Tauntek 1.20 eprom in it (fitted years ago) and now I’ve reset it and done a CAL it seems that one of the problems is that the RAM memory slots 000 to 199 are empty of patches (in the Matrix 1000 they’re only copies of ‘best of’ patches that also exist in the other eight banks 200-999) and that tells me the battery is probably flat, so I metered it in circuit and it’s completely flat

Luckily about 10 years ago I bought some CR2032 holders which have the same pin distance as the soldered-in 2032 cell, so I’ll fit that and put a new CR2032 in (then somehow send the sysex ram banks over to it, which I’ve never done and can I do it from an iPad midi app I already have? I’ve no idea – or can it be done from Logic Pro X on the MacBook such that I can understand how?)

Fortunately I can’t be arsed at the moment to unscrew the main board and lift it up and unsolder the cell, so I’ll do it not today

The hum was probably the volume pot on the front (which is very robustly mounted on an internal frame, the knob is captive but only rotates it, pulling it just pulls it off the shaft a bit but still allows rotation, which is a thoughtful design) so while I’m dismantling it further (only the top case is off at the moment, I had to prod the power circuitry about to see if that was a contributing thing to the hum as it so often is on those units, but no, it’s fine) I’ll probably clean the pot, by dismantling it and doing it properly rather than spraying goo into it (which I don’t have) – but, not now, I’m tired