Note: links to listings are affiliate links for which the site may be compensated.

via
this auction"Hello – This ESQ-1 was used to produce several children’s albums back in the day before I inherited it. Since then, it was primarily used as a MIDI-controller in my own production set-up. It does have its share of cosmetic scuffs and blemishes, but it’s built like a tank and everything is in working condition including all keys, buttons, and the LCD screen.

However, it will require an internal battery to be replaced. When powered up, it displays “Warning - Battery Voltage Is Low”. The purpose of the internal battery is to save the sequences and patches in memory when powered off."