Bizarre 01W Problem...

[ausser]

Hi,

I've used an O1W PROx for about 25 odd years. the last 15 or so as a main Studio Motherboard - 88 weighted keys for midi into a DAW.
The thing is a monster - REAL WEIGHTED ACTION not hammer and so weights a ton. Nevertheless I used to haul it into solo gigs back in the day...
It has never let me down.
The battery died of course a few years back and the aul DD, but since I've only used it as an 88 Piano midi board for the last 15yrs or so - I didn't bother replacing the battery or fixing the DD, rarely even loading the Factory banks on startup to regain the patches from INIT 001 etc.

The other day things went awry...
When I fired it up, the first thing I noticed was - no keys sounding.
A quick scale over the 88 alerted me to 2 specific things.
1. One key was sounding. 'B' That is - 'B' is the only key sounding across the whole board - B1,B2,B3 etc.
2. B5 is different. It sounds and also the octave from B5 to B4 except the other keys from B5 to B4 are very feint sounding, you barely hear them and also they are sustained - even without a damper pedal plugged in.

All other keys across the board except what I mentioned above DO NOT sound.

Also, there is no other Midi key output except for the keys I have mentioned above.
And Vel Sensitivity is working on the 'B' keys.

After a frustrating button pushing and resetting afternoon, I noticed that the entire Sequencer has failed. That is, I can't access the O1W's Sequencer.
When I press the SEQ button on the Left-hand-side panel it refuses to enter Sequence mode.

Also the 'H' button along the LED display isn't working and the 'Page UP/DOWN' buttons aren't functioning. All other buttons appear to be functioning normally.

Any suggestions or pointers greatly appreciated.
Ausser.

[voip]

Get the power supply checked. It could be on the way out.

.

[ausser]

I was thinking that could be it.
Hopefully it is.
Aus.