MT1000 self check tone and a mysterious repair

[indigo]

We had a MT1000 VHF that exhibeted an odd condition when turned in for checking: when powered up, instead of the standard microprocessor self check tone it would sometimes do nothing (checked it by hitting the squelch button, nothing), but more often than not it would beep successively at least several times (each beep maybe about 1/2 second/ea.), sometimes a few, sometimes almost continuously, almost like it was in a looped self check or power up mode? Was checked with several power sources so it wasn't a power issue (unless it was one mechanically with the unit itself - read on: When it hit the bench, we began disassembly but got distracted and only got so far as removing the bottom battery mount and the front. Upon returning to the bench a day or two later, further evaluation was put on the backburner due to other issues, so it was reassembled and tagged for further checking. But before shelving it, it was tested again and strangely, it powered up immediately, self check toned normally, and was cloned to further check it out - and now it's perfectly operational, cloning was executed in normal fashion, and "further evaluation" apparantly not being needed right now. It has been working fine since. My question is, "what might have happened and how did it mysteriously 'heal' itself what with just a minimal amount of preliminary disassembly, then reassembly?

[Tony Soprano]

A couple of things come to mind here.

It would not be unusual to see this if the screws that hold the battery contacts, or the chassis to the baseplate, were loose, causing strange power distribution.

It would also not be unusual to see the two header plugs that connect the control top and power/PTT flex to the controller package pull out a little bit. That would cause real weirdness to happen. If there is no retainer piece present, they will work themselves out with normal duty.

These would be places to start.

Tony