Some people just aren't good with modern devices. Characters with this drawback suffer a -2 penalty to the Repair skill at all times. In addition, when a hero uses a mechanical or electronic device, a roll of 1 on his skill die (regardless of his Wild Die) means the device is broken. The damage usually requires a Repair roll at -2 and 1d6 hours to fix.
Savage Worlds Deluxe Edition p. 29