MCX1000 Issue?

[Roadwolf]

I am having a strange issue with my MCX1000. Worked fine a while ago, but I had it in storage for several months. Recently installed in my vehicle. Never powered up.

So I took it out and brought it into the shop, powered it on the shop power supply, and tested it. At first I tried powering it up with no microphone, speaker or antenna connected. It reset during selftest each time. Then I connected the microphone and antenna, and it worked! yay! Until I changed the channel a few times, then it started resetting again.

I then connected the speaker and it worked again! But I changed the channel a few times more and it did the same thing.

I am kinda stumped, and thinking that the unit might be fried

[Roadwolf]

A bit of an update:

Shortly after posting my previous post, the radio turned on and read I/O TEST

About 2 hours later I powered up the radio again, and it worked! I could change channels, and hear audio. But that only lasted for 5 minutes. Then it began doing SELFTEST and then resetting again over and over. This seems to happen every time now, I wait a while, turn it on, it works, but then it does this selftest cycle. I am thinking that something is overheating inside. Will work on it tomorrow night hopefully and try to diagnose which chip is heating up.

If anyone happens to know of a digital copy for the schematic for the radio, I would appreciate any links or emails

[NSPD]

Leaky Caps? Not sure if this was an issue with the MCX1000, but the symptoms sound the same.

[Roadwolf]

Could be! That would be a nice easy fix.

[Roadwolf]

It seems like it may have been U50, which seems to be a 51R82609 8 pin DIP. Spraying that general area with freeze spray instantly returns the unit to normal operation once it begins resetting. Upon further investigation it seems someone prior to me, tried adjusting the power higher with the trim pot, which seems to overdrive that IC. Lowering the power trim pot a tad seems to have fixed the problem.

Now I just need a fricken microphone that works