Lightning Strikes Lightning can deliver a charge of millions of volts, and if your home is hit directly, significant damage will likely be the result. Good line protection equipment can often help reduce the chances of catastrophe should lightning strike but due to the sheer power involved in a direct hit, there is a good chance that even with protection your equipment may be damaged. A direct hit with lightning is fairly rare, but there is another lightning-created risk that more commonly affects PCs. Any wire that comes in from the outside and attaches to your PC can become a conduit for a pulse of destructive energy. This also includes the telephone line.
Most power supplies can handle a reduction in the nominal voltage that it is expecting.
Any reduction of voltage below 95 V for more than a fraction of a second is likely to cause the power supply to either shut down or malfunction. Brownouts are extremely common, and can lead to mysterious problems you would never blame on the power system. You can sometimes detect a brownout by noticing the lights flickering or dimming which occur often during heavy load periods. As our electric grids become more and more taxed due to increased demand, the incidence of brownouts will increase. Blackouts A blackout, of course, is when the power totally fails.