you could try doing a reset to see if that fixes it....it may be that your battery is dead
(if its your battery then any electronics technician can fix it locally)
http://www.circuitbenders.co.uk/forum/index.php?topic=1616.0;wap2If you are getting the BAd error message at start-up you can try clearing all memory using the following button push sequence, but remember this will wipe any patterns you may have stored:
Switch on.
Press the song/segment button so that the segment mode is selected.
Hold down the Insert/Erase button and press the Cassette button once, do not release the Insert/Erase button.
The message "poof" appears in the screen (no, really).
Whilst still holding down Insert/Erase press the Enter button.
Switch off and on again - all memory should now be cleared and the BAd message should be gone and the Drumulator should work normally.
It's also worth changing the internal battery as they were only meant to last for 5 years or so - you need a 2/3 AA, 3v Lithium battery with solder tags (2 tags not 3).