单项选择题 A laser printer displays ‘perform user maintenance’. The manufacturer’s information was not available when the user performed the maintenance, and the laser printer continues to display the maintenance code. Which of the following items needs to be performed?（）

单项选择题 A technician has just installed a new power supply into a desktop computer and now the computer will not turn on. Which of the following is the MOST likely cause?（）

单项选择题 A legacy PCI IDE controller card does not recognize a new IDE HDD. Which of the followingmaintenance techniques would BEST resolve this situation?（）