I can't count the number of units that I have to service that have had ESD damage. One note to anyone that decides to attempt servicing or upgrading hardware their computer themselves is to NOT unplug the unit from the wall. That power cord, when plugged into the wall provides the only ground you'll find in 99 percent of peoples homes or offices. The power supply has a metal case around it and this will protect you from any lethal voltages so you will remain safe while still being plugged in. I still use a ground tester and wrist strap while on a clients site. The tester determines if the ground is valid and the wrist strap to insure I'm grounded even if the unit isn't. Modems are a particular beast because they have some transformers that can induce some rather high static charges.