Ref: HYC198485 When you send a print job to the printer, you expect the device to respond and start printing. If the printer remains asleep, however, you quickly can fall behind on your work. Resolving the problem quickly can make the difference between work getting done and the potential loss of time and money. Several factors may result in a sleepy printer, but understanding the most common culprits may help to rouse the device from slumber.
More details: Hp Printer Won Wake Up From Sleep Mode