Stereo static in cockpit and bridge

[Pocumtaco]

I bought a 2005 420DB recently. The port-side cockpit and bridge speakers play only static. Starboard are ok. Salon speakers are ok. From what I have read, this is likely a blown amplifier. Questions:
1. Where, exactly, are the amplifiers located? Behind the port sofa is the best I have been told.
2. Any recommendations on a replacement unit?
3. I am going to attempt to do this myself - I'm pretty handy, but no master electrician. Any specifics would be appreciated!

 

[rggale]

I have a similar issue on my boat. All of the speakers have no static, except one speaker that has intermittent static. Would I have the same diagnosis (blown amplifier)?

 

[brewster16]

Id certainly guess a bad speaker not a bad amplifier. Why not just swap the static speaker and see if that solves the problem?

 

[Wylie_Tunes]

Given that the issue is isolated to only the port side speakers, the problem could be starting at the head-unit. First, find the amp and confirm which speakers are driven by the external amp. This is easily done by removing the RCA cables, then powering the system up. Any speakers left playing, or NOT driven by the amp. Next, swap the RCAs left and right, power back up and see if the issue moves or stays. If the problem moved with the swapped cables, its upstream of the amp. If the problem stayed with the port speakers, it could be the amp or any single speaker that wired in with the others on a single chnl.

 

[Pocumtaco]

Given that the issue is isolated to only the port side speakers, the problem could be starting at the head-unit. First, find the amp and confirm which speakers are driven by the external amp. This is easily done by removing the RCA cables, then powering the system up. Any speakers left playing, or NOT driven by the amp. Next, swap the RCAs left and right, power back up and see if the issue moves or stays. If the problem moved with the swapped cables, its upstream of the amp. If the problem stayed with the port speakers, it could be the amp or any single speaker that wired in with the others on a single chnl.

Thanks, Wylie. That is good logic. I will use your algorithm to isolate the source of the problem.
I still need to find the amps...
Regarding the head unit - anyone know the trick for releasing it so that it will slide out of it's housing? There must be a way to unlock whatever is holding it in there (?).

 

[katricol]

Could be just a bad ground, no?

 

[Wylie_Tunes]

Could be just a bad ground, no?

Not likely if the issue is just present on one side. Since the head unit and amp share the same ground plane, a bad ground would be heard on all speakers.