ICOM M421 - shutting down

wetterthebetter · 09 July 2005, 00:30

Jon Brooks, you're a popular fella! Here's another question for you. I've just installed my new Icom 421 and when the PTT button is pressed the radio shuts down, release it and it comes back on! Any ideas? Also, I have linked it to my Garmin chartplotter. Is it important that I make certain settings on the either the VHF or the plotter for them to speak to each other? Thanks.. any advice most welcome.

Hightower · 09 July 2005, 09:17

Are you sure you've got the Antenna plugged in correctly, if you haven't the VHF can get damaged and shut down to protect its self.

Shaggy · 09 July 2005, 10:22

Does it shut down on low power too?

I ask as it might be high resistance on the battery terminals, so it cant draw enough current on TX.

Shaggy

wetterthebetter · 09 July 2005, 11:17

only on high! Shall I just operate on low? And what's the reason and how can I stop it shutting down on high? Thanks v. much.

Jon Brooks · 10 July 2005, 07:19

If it only shuts down on high power then you have a power feed problem.
It would seem the radio can not draw enough current.

I would suggest checking all the power connections.
Make sure there is no corrosion on the battery terminals ect.

Any more problems let me know.

Regards

Jon Brooks · 10 July 2005, 07:21

Also the Garmin will be set from new to output "Garmin Data" and not "NMEA"

Press menu twice, scroll down to "comm" then set it to "NMEA in/out"

If you don't set this right the GPS will not talk to any device needing NMEA.

Regards

wetterthebetter · 11 July 2005, 23:55

Thanks for the replies. Am checking power supply; all initially looks OK. Have altered the setting on Garmin but still saying no position on VHF.

Jon Brooks · 12 July 2005, 08:35

If you have the Garmin set right and no position it would suggest that the two are not wired together correctly.

From the red phono on the M421, inner to NMEA OUT +, outer to NMEA OUT - or to the Ground (black wire) of the Garmin.

If the power connections are all ok and the unit shuts down on high power TX this would suggest the battery is not up to the drain.
The only reason the radio would shut down in the way you say is because of lack of current to drive the radio.

Regards