With all control knobs facing towards you, Remove top cover, Notice Front Left corner is the processor with a crystal mounted on top.

Extreme left of the radio you will see a row of pads, All empty except for a diode to the front and one to the back, Notice 7 or 8 spots for diodes, But only 2 installed.

REMOVE the FRONT diode closest to the head of the radio with a small soldering iron or tool.
Turn the radio back on it will automaticaly reset.... 