Ah McNaughtical, its not a problem, its an opportunity for you to learn. And also best done in the security of the marina/anchorage where you can ask the neighbours for help if you get stuck. A few simple things to check would be loose connection and corroded joints or hot joints.

Loose connections can be found by wiggling the wires where they are connected and see if there is any movement in the connection point. If you find a loose connection and need to tighten a screw, be gentle with the screw, as the heads can be snapped off easily. Some are made of steel but some are only brass. Also gently wiggle the wire as you tighten it as this will make the conductors spread out as the screw tightens onto them.

The loose connection could also be a push on connector. Some of these can be be squashed a bit with a pair of pliers to get them clamping on better.

Some times where you get a loose connection you may also get burning of the wire/insulation. If the wire is discoloured from heating, then the burnt bit may need to be cut off, and the wire stripped back to redo the connection. Warning - Hot joints and burning wire can lead to a fire on your boat so if you open up the switch board panel, have look around at all the other wires to see there are no signs of burning.

The "Green Death". Bare copper corrodes in the marine environment and this is why tinned (silver coated) wire is normally used on boats. You can normally see this corrosion by its green colour and it will be causing problems, so it must be cleaned off or cut off and the connection re-made.

Because you said the VHF was still operating (but making crackling noise) I can assume your fuse had not blown (or circuit breaker tripped). Fuses are either okay or blown. Simple little buggers, but circuit breakers can have an intermittent fault. I had a 15 am C/B on my boat that ran the Hot Water system (12A). It would hold in (stay on) for about 15min and then trip. I checked the current (with my amp clamp) the Hot Water system was drawing and it was 12 amps so the breaker should have held. I changed the wiring that feeds the hot water system to a spare breaker and had no more problems. Faulty C/Breakers are a rare fault, but if your VHF and music box are both connected to one this is another possibility.

See how you go with your opportunity to learn and give us more information on your setup so we can assist further if needed.

Cheers

Or maybe the music box has died and there is nothing wrong with the electrical system.

Thanks very mych fir the detailed instructions Crusoe. I took the connecting wires off one of the speakers the other day as I tore off the crappy old plywood off this wall it was mounted on but there was no where to easily mount it back.. would that have caused the problem?

Disconnecting the speaker wires shouldn't be a problem. But you should put a bit of insulation tape on them to make sure they don't short together or come in contact with some other metal object or appliance on the boat that may have an electrical connection back to the battery. I should have to say this but make sure the wires aren't laying in the bilge where they may become wet. When I purchased my boat I found 5 separate live (12vdc) wires laying in the bilge of my steel hulled boat.

With regards to a possible flat battery, I would imagine you have other things (fridge, lights, water pumps etc) running whose continued operation would indicate the state of the battery. Get a flat battery and everything begins to stop working. But still worth while checking the battery volts to make sure the music box is not the first to drop out due to under voltage.

Is your boat in a marina and the batteries on a 240Vac battery charger? Or relying on solar/wind. Been a bit of overcast weather lately.

Thanks heaps. I'll get a voltage meter before I go back in my bext days off

My two bobs worth is the aerial connections.