Audio Systems: Head Unit Not Working, sony head unit, electric antenna

Question
Hey, I have a 98 honda civic, and my sony head unit has been
working fine ever since I got it about a year ago. I hit a bump in
the road, and now it won't go on anymore. I checked the fuses,
fine. I made sure the power cord was plugged in. I think maybe
the cord might have disconnected on the other end? Where does
the power cord go from the head unit? Thanks

Jesse

Answer
Hi Jesse,
Don't ya just love those bumps in the road (NOPE!)
Have you been playing at "Dukes of Hazard" again?

Power cord (loom) goes to the fuse box, one for ignition and one for perm 12v.

First thing to do is to check what's dead.
using a meter at 20vdc of 12v probe lamp,

1/ check for 12v with ign off, if good go to 2 if not find break or fuse fault then go to 2

2/ check for ANOTHER 12v with the ignition on but radio off if ok then go to 3 if not trace as above and thenwhen fixed go to 3

3/ check for a THIRD 12v with the ignition on and radio on, this is the anttena/amp feed OUT. (This isn't vital unless you havean electric antenna or amps but it should be there)
4/ If all above check out then check for earth by taking a lead from radio chassis to known earth point.
should all work.
5/ If all above check out you have a faulty head unit.
Hope that check list helps. Peter