Blinking Causes - Utility
The utility power distribution system is not unlike the wiring in your home. There are large lines to carry large quantities of power and smaller lines for smaller quantities. These lines are protected by fuses and circuit breakers, just like the lines in your home.
If something comes in contact with the power line, such as a tree limb or small furry mammal, the power line reacts to this "short circuit" by increasing the current flow to and through the line.
The increased current flow is sensed by a circuit breaker. The breaker interrupts the power to the line for a very short time - usually less than a second - to allow the short circuit to go away. This protects the line from serious damage and prevents a longer term outage. After the short interruption the breaker resets itself and restores power to the line.
If the circuit is okay again the power stays on. If the short circuit is still present, the process is repeated to give the line one more chance to clear. If the line doesn't clear then the breaker trips and must be manually reset after the line has been checked and or repaired. This is why you will often see the lights blink twice before they go out for longer periods.
Occasionally, utilities must change the way power feeds into the lines serving your home. This may be due to a temporary overload, damaged equipment or maintenance work being done on the lines. When utilities make the switch you may experience a short power outage - again usually less than a second. This outage is more than enough to cause your computer, VCR or clock to lose data or at least the information stored in its Random Access Memory.