The Complementary Metal Oxide Semiconductor, or CMOS, is a motherboard chip powered by a battery. This chip stores the Basic Input/Output System (BIOS), which is responsible for the first phase of the computer booting process; it also stores basic computer settings such as hardware configuration and the system time. Resetting the CMOS may resolve certain hardware problems on your HP Pavilion M370N, but one of the most common reasons you may need to take this step is if you or an employee set a BIOS password and then forgot it, rendering the system unbootable. Clearing the CMOS erases the BIOS password along with all hardware settings, forcing the computer to rediscover them at the next boot.
Shut down your computer and unplug all cables.
Press and hold the "Power" button for a few seconds to discharge residual power from the motherboard.
Loosen the two large screws holding the left-side panel in place (the screws won't detach completely). You should be able to loosen these by hand; otherwise, use a Phillips screwdriver.
Slide the panel toward the rear of the computer to remove it, and then set it aside.
Place the computer on a table or another flat surface (not a carpet).
Touch an unpainted metal surface on the computer case to ground yourself.
Look for the jumper marked "J19" on the motherboard. This jumper is located next to the CMOS coin battery.
Remove the jumper cap attached to pins 1 and 2.
Move the jumper cap onto pins 3 and 4 and wait about 10 seconds.
Replace the jumper back onto pins 1 and 2.
Refasten the side panel and reconnect all your peripherals and cables.
Start the computer. Enter the BIOS setup page if necessary to reprogram your system clock. You'll probably need to press the “F2” key to do this.
- Virtually anyone can open a computer and reset the CMOS. Therefore, if your office computers have BIOS passwords to prevent unauthorized access, consider locking the side panels. A small metal loop on the back can be used to padlock the panel.
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