Static can be lethal

I don't know if you know of the plastic pushbutton panels - the ones with the domed plastic? Well they are very good as waterproof buttons but they crack or become stretched over time and lose their clicking ability. It seems they are also susceptible to static discharge when they crack and can easily be a conduit to your driver chip(or your precious CPU). I received a job with just this problem. The driver was a 74HC138 multiplexer that is being used to pull down on the lines that are driven from a logic buffer. The static discharge from the operator had damaged the IC and caused one of the pins to remain low. This had the effect of disabling a row on the pad but it could have been much worse if the discharge was larger or got into something like the CPU.

If you are looking for a good push button solution to your product or you're the owner of a product with a button pad like this, it would be a good idea to remember this could happen. If its a PLC or something expensive you may want to place some laminate or insulating cover over it during the winter months - or touch the person next to you before using it to prevent damage to the product ;)