Faulty Reed Switch

[1BrickShort]

I have a reed switch that has been working properly for multiple cycles, then out of the blue it is showing a short circuit. The reed switch itself has been soldered to a circuit board and embeded in epoxy, so I do not have the luxury of being able to physically touch the switch or board.

Has anyone seen an effect on a reed switch that would cause it to suddenly short for no good reason, then remain shorted indefinetly even though there was no magentic field present?

Is it possible for a voltage spike to cause this? What else could cause this effect?

I am confused by this.

The idea of embeding the switch assembly in this expoxy has been proven through experience on the product line, so I am fairly convinced that the effect is not coming from the efects of the epoxy...

Does anyone have an idea as to what this could be?

1BrickShort

 

[IRstuff]

As with any switch, overcurrent can potentially cause the contacts to weld together

TTFN

FAQ731-376

 

[1BrickShort]

Well, the welded reeds was the correct answer. I found a potentiometer this morning that was shorting in the circuit and causing the failure. Through testing I could repeat the effects consistently...the conclusion is that we shouldn't nessisarily buy from the cheapest bidder!!!

Thanks for the input

1BrickShort