In a message dated 10/17/03 8:37:41 AM, gilwein at walla.co.il writes: << Can EPROM programming go defected if you power a synth up without the back battery in the circuit ? >> No. EPROM's can indeed go bad, but not because of a missing or dead backup battery. BTW, EPROM failure is VERY rare. Look elsewhere for the problem first. Michael Bacich