After many years of flawless operation the ICOM 502 we installed in our boat developed an odd problem the other month. After about 20 minutes it would lock up. Part of the screen display would go away although the channel number would remain. But none of the radio's operations worked--- it didn't receive, didn't transmit, we couldn't change channels, etc. Turning the unit off and then back on restored complete normal operation for another 15 or 20 minutes at which point it would lock up again.
I removed the radio from the panel and disconnected the Command Mic to see if it was the problem. It wasn't. I checked the power going to the unit and it was a proper 12.5-13 vdc. Even when removed from the panel it exhibited the same lock-up problem after about 15 minutes of operation.
So I took it to the electronics shop in our marina where we had purchased it. Jerry could not get the radio to lock up, even wrapped in a plastic bag to heat it up, until he finally left it on in his shop all day and all night. The next morning he came in to find it in its locked-up condition.
So he sent it to ICOM in Bellevue, Washington. They couldn't get it to quit but after Jerry told them what he had experienced, they put it through a full week of testing in cold temperatures, hot temperatures, vibration, etc. No luck, the radio ran perfectly the whole time.
So they sent it back to Jerry. He got it back right after I left for China for three weeks, so he put it on his bench, hooked it up, and let it run for the whole three weeks. No problems at all. So Monday he put it back on the boat and I'll re-install it this weekend and we'll see how it goes.
Hopefully it will continue to run fine. But if it exhibits the same problem, does anyone know enough about VHF radios to hazard a guess as to which board (function, circuit) in the radio could do this so we could tell ICOM to simply replace the component? Jerry mentioned the microprocessor could be the issue, but I'm curious if anyone here who truly knows about radios has any other ideas. Thanks.
-- Edited by Marin at 15:53, 2008-12-30
I removed the radio from the panel and disconnected the Command Mic to see if it was the problem. It wasn't. I checked the power going to the unit and it was a proper 12.5-13 vdc. Even when removed from the panel it exhibited the same lock-up problem after about 15 minutes of operation.
So I took it to the electronics shop in our marina where we had purchased it. Jerry could not get the radio to lock up, even wrapped in a plastic bag to heat it up, until he finally left it on in his shop all day and all night. The next morning he came in to find it in its locked-up condition.
So he sent it to ICOM in Bellevue, Washington. They couldn't get it to quit but after Jerry told them what he had experienced, they put it through a full week of testing in cold temperatures, hot temperatures, vibration, etc. No luck, the radio ran perfectly the whole time.
So they sent it back to Jerry. He got it back right after I left for China for three weeks, so he put it on his bench, hooked it up, and let it run for the whole three weeks. No problems at all. So Monday he put it back on the boat and I'll re-install it this weekend and we'll see how it goes.
Hopefully it will continue to run fine. But if it exhibits the same problem, does anyone know enough about VHF radios to hazard a guess as to which board (function, circuit) in the radio could do this so we could tell ICOM to simply replace the component? Jerry mentioned the microprocessor could be the issue, but I'm curious if anyone here who truly knows about radios has any other ideas. Thanks.
-- Edited by Marin at 15:53, 2008-12-30