Resetting Series 2000 switch

Greetings

Just before Xmas 2004/05, I was asked to take a look at an installation that is now 5 years old.
The new owners were having trouble with 3 x ?2000 Series? switches.
Two were definitely faulty and replaced, the third seemed to come right after I had disconnected and then reconnected the unit back to the system. I was called back last week, they are having problems with the same switch no working at all this time, no LED lights, no switching. Again this unit seems to have come right after a power down and restart.
Could this be a problem with the hardware / software from this era unit or is this unit simply on its way out.

Colin Smith

 

I've seen it too.

I have seen this happen in my home installation with three vintage 1997 units. In all cases, taking them off the wall and allowing them to cool for a few minutes put things right temporarily. The problem in all three units stemmed from either a faulty transistor or solder joint in the unit's internal high-impedance power supply circuit. I re-soldered one and it was good for another year, so it seems that the problem was related to a transistor overheating..

One of the alternatives specified for the (surface-mounted) transistors in these units had a lower than usual specification for maximum temperature of soldering, and it is possible that some were inadvertently stressed in the soldering phase of the manufacturing process. The design of that part of the unit circuitry has been cleaned up a bit in the last 5 years, and I believe that the suspect transistors are no longer specified as alternatives.

Don