out of no where, the laptop ProBook 4525s would not turn on...I removed battery and pressed on switch to drain...nothing...so leaving the battery out, 1 plug and unplug the power cord (sometimes 30 to 40 times) and press the on button...eventually it boots up just fine...sometime it only takes a few time and occassionaly it starts right up..it will then run all day with a few exceptions when it will just shut down for no reason..but it always boots up again..eventually