Navman 7200 VHF radio advice needed

N

Newman

Well-Known Member
Joined
9 Jan 2011
Messages
106
Visit site
Evening all

A friend of mine recently bought a nice little Maxum cabin cruiser and is thoroughly enjoying it. One slight problem with the radio though.

Today he was using the radio (with GPS fed from it) when both suddenly stopped working. Checked the voltage with a neon tester and had 12 volts arriving at the final connectors behind the radio. Turned the radio on and the neon dropped to 6 volts but radio showed no signs of life.

Any advice/suggestions will be greatly appreciated.

Many thanks
 
Newman said:
Evening all

A friend of mine recently bought a nice little Maxum cabin cruiser and is thoroughly enjoying it. One slight problem with the radio though.

Today he was using the radio (with GPS fed from it) when both suddenly stopped working. Checked the voltage with a neon tester and had 12 volts arriving at the final connectors behind the radio. Turned the radio on and the neon dropped to 6 volts but radio showed no signs of life.

Any advice/suggestions will be greatly appreciated.

Many thanks
Click to expand...
Battery dead?
 
Hello Elton

Radio first went dead while the boat was at sea with the engine running. Checked supply back in the marina and the boat batteries were healthy.
 
bad connection to the el.panel (if it goes there...) something rusting/bad earthing?

Try a clean run of cables from the battery to establish that the fault is at the radio, then go on from there. Bet it's cabling

V.
 
Looks like a dirty or faulty connection somewhere.

With no current draw you will see 12v, but as soon as curent is required the voltage plummets. Check the fuse first, as it could have blown and left a partially conductive pathway (dry fuse), loose connector, etc.

Check back along the feed line to see where the volts drop stops when the radio is switched on. Unless transmitting the VHF draw will be fairly low, but this would be my first investigation.

Are other devices affected or is it just the VHF and GPS and are they from the same supply source. Ideally the VHF should have a direct feed with minimal switches from the battery with its own fuse, that way if the electrics generally pack up the VHF supply is more likely to remain available, which could be critical in an emergency.
 
Newman said:
Hello Elton

Radio first went dead while the boat was at sea with the engine running. Checked supply back in the marina and the boat batteries were healthy.
Click to expand...

Did the VHF radio go dead as it was turned on or, more probably, as the transmit button was pressed?

You will find that the radio has either a dry joint on the PCB inside the set or the supply from DC supply to the VHF radio has a 'loose' connection which goes high resistance whenever current is passed along the wires to the radio. ;)

.
 
superheat6k and lenseman

Many thanks for the replies. Am signing out now but will digest all the replies tomorrow and make a 'to do' checklist together with a list of bits and pieces required.

Where would we be without the assistance we get from people such as you on the forum !
 
99% chance power prob.Radios very rarely go wrong.
Check wiring from radio right the way through to battery.
Look at ALL connections esp. any inline fuse holders and bits of added choclate block etc.
Sometimes you can actually "feel" the problem connection as bad joint will sometimes get warm,the heat will frequently also cause any nearbye plastic insulation bits to deform or even melt.
In worse cases just run complete new length of cable if unable to get to problem because hidden behind bulkheads etc.
Check that there is no corrosion on SO 239 socket on back of radio.
Aerials can get water in them,it runs down inside of cable by cappilary ? action and directly in radio.
Normally traces of green isn gunge present somewhere on plug .
 
You must log in or register to reply here.

Share this page

Top