Review of Minitor 4 problems

[WB2IID]

Okay, out of 30 M4 pagers bought a year ago more than 25 percent of them have had to be sent back for intermittent receive problems. This doesn't count the one I could fix by myself.

I just sent the latest bad apple off to Elgin this morning. Before I did, I performed a microscopic inspection of the RF deck to see if there were any loose connections. I even resoldered the loop antenna connections. No soap.

Anyone have any "fixes" that they can share? Here are the typical problems and solutions as I currently understand them:

Intermittent receive: There are two - one which results in the squelch opening and pouring out hash, and one that does not - the radio simply does not receive unless you press on the speaker.

1. The open squelch problem: Any ideas? I think something is happening under one of the shield cans but I have not ventured to peek inside - yet.
2. The other receive problem (you press on the case to receive): May be related to # 1 but I've also heard that resoldering the places where the antenna loops attach to the board is the magic fix. This does NOT cure # 1.
3. Receive is fine but no tone decode: This is the classic broken solder joint on the IC behind the belt clip, which I was able to fix on one of the fleet.

Anyone have any additional information?

Joe