Just got a Craigslist 2007 Cobra 29 LTD Classic. Will not power up. Thought would probably be the reverse polarity diodes D23 or D8 but no such luck. The audio IC has voltage at pin 1 which I found on another site to check. The switch has 13.8 to all terminals red, orange, green yellow, white black. Another forum advised that if I jumped terminals that the radio should power. Pretty sure the switch is shorted but not sure what to disco and jump. Any help would be appreciated. Visually I do not see anything that looks burnt(resistors/caps etc.) I do understand that if was reversed could have taken out a bunch of stuff. I want to try to chase it to the end. Thank you.