Nowadays one gets to handle plenty of populated ready to use PCBs - be it a MCU development kit or a PCI modem card or a DAS card or whatever.

In all these cases there is this warning about Electrostatic Sensitivity ( the yellow triangle with a hand crossed out ).

Handling these in the lab or assembly room is no problem where one can exercise caution - but what about the field - where also you need to handle these ?

In fact recently we replaced a Graphic LCD module in the field and right from begining it did not work. We then had to replace it with another one to get it going. Now the vendor has taken refuge under the ElectroStatic stuff.

Can someone clear up this a bit more ? I am sure not all VLSICs and the like are so tender - that they die instantly at the user's hand. I have heard of input protection devices both in power On and Off conditions. How effective are these then?

At this rate it appears that I have to have a DMM permanently rigged up between my hands and GND!! And handle items only when the DMM reads a low value...

Raghu