When we had our first child, we had an audio monitor that consisted of 2 pieces: a microphone with a wireless transmitter and a speaker with a wireless receiver. Thus we could hear the baby from afar.


Times have changed. Now the hospital uses disposable diapers rather than cloth. Infant monitors have improved.


We have a Safety 1st video monitor which consists of a little TV set wireless receiver and a little TV camera. It’s quite useful.


However, the power supply for the camera seemed to be flaky. Every once in a while, the system failed. We’d just see static on the TV monitor. Upon further inspection, the camera’s green LCD would be off, indicating lack of power.

The power jack plugs into a simple hole which has a rod for one contact and a metallic contact for the other. It looked as if the metallic contact wasn’t making contact with the plug, so I bent the contact a little. Sure enough, it worked, so we’d be in business again.


However, the intermittent failures continued to occur. I’d have to dismount the camera, get out the toolbox, rebend the contact, and we’d be ok for a while. This got frustrating. It dawned on me from past experience that maybe the problem wasn’t the metallic contact, but could have been a cold solder joint.


Many years ago, I installed a remote keyless entry system to my 1990 Camry. I bought a kit from a mail order firm and it worked fine for many years. However, it had a cold solder joint. Diagnosing it was not simple, as there were many integrated circuits. Luckily, I had made myself a Heathkit (remember those?) oscilloscope with which I could trace circuit signals. Once identified, the fix was easy. Just whip out my soldering iron and re-heat the joint.


I did just that for the power contact on the TV camera, and it’s since worked like a charm!


I wonder how many consumer electronic devices have failed due to such a simple problem?