[GooseF22]

if you reverse polarity charge the DX7, it will blow the fuse in the mother b oard. its a 2.5 amp shorty. dont ask me how I know.

If the radio wont memorize the settings, barring an internal failure, you have a bad battery. plain and simple. the voltage is depressing somehow. change batteries before sending it in. Make sure you exit the setup menu before powering off. both left buttons

Load test your battery. as the battery dies, the eprom is disabled....then later the display....then finally the transmitter. ITs designed that way to let you know somethings wrong. If the emprom wont save and the voltage is up, it could be too high. Your voltage regulator internally could have problems too. requiring repair.

Ive had mine over a year and we have put switching regs on the board, so we get about one month from a charge.