NO Sound from Speakers Accord Euro - Please assist/ guide

Hi All,

I am new to this site and wondering if i can get any help.

I have Accord Euro 2008. My car radio is working fine but i don't hear any sound from any of the speakers.

This happened since i change battery and plugging in positive to negative. I have showed to local electrician. All fuses are fine. I even changed the radio and amplifier (located in boot) but still doesn't help.

Three Auto-electricians checked but no one can diagnose the problem.

Can someone assist / advise if they came across similar issue or know a good Electrician or Car Audio repair in Sydney who can really help.

your help will be much appreciated.

Thanks and kind regards

sorry, did you plug the positive to the negative of the battery and vice versa?