m1225 blanking out

[fire_marshal_bill_1075]

A fellow officer came to me with his m1225 and said that when he would transmit the radio would blank out. What I found is that when it was in scan mode and you picked the mic off the hook and transmit right away the display would fill up with the zeros like when you turned it on for the fisrt time. Occasionally I would have to change the channel up or down and then back to the original or it wouldn't transmit. And once in a while the radio would actually shut off for about a sceond and then come back on.

I've checked the power, mic and antenna connections and nothing appears to be loose. I'm lost. Any and all help would be appreciated. TIA.

Bill

[Al]

Unless you can acutally test the M1225 with a known good power supply to verify whether or not the problem is the M1225 itself or the installation, I would suspect a high resistance in either the positive or ground wiring between the radio's power connector and the vehicle. Since the M1225 draws much higher current when the transmitter is keyed than when it's in receive mode, that's when any excessive resistance in either power lead could cause enough voltage drop(read - low voltage at the radio terminals) to cause the uP in the radio to reboot....which seems to be what you're describing.

[wavetar]

I'm willing bet if you follow the power wires back, there'll be one or more spots where the cable has been cut/worn/punctured and water has made it's way in, corroding the cable. Also happens if butt-connectors have been used to splice the cable...or it could even be a poor ground.

Todd

[n5tbu]

Ditto what Todd said.partially unplug the powercord enough to probe with an analog meter(probe BOTH plus and minus at this point)...look for voltage drop when transmitting.
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