HP 550 manual Description Spare part number RTC battery 449137-001

RTC battery

NOTE: Removing the RTC battery and leaving it uninstalled for 5 or more minutes causes all passwords and CMOS settings to be cleared.

Description	Spare part number
RTC battery	449137-001

Before removing the RTC battery, follow these steps:

1.Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.

2.Disconnect all external devices connected to the computer.

3.Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.

4.Remove the battery (see Battery on page 39).

5.Remove the following components:

a.Hard drive (see Hard drive on page 40)

b.Optical drive (see Optical drive on page 46)

c.Keyboard (see Keyboard on page 50)

d.Switch cover (see Switch cover on page 48)

e.Speaker (see Speaker on page 53)

f.Display lid switch module (see Display lid switch module on page 54)

g.Display assembly (see Display assembly on page 55)

h.Top cover (see Top cover on page 60)

i.System board (see System board on page 66)

Remove the RTC battery:

1.Turn the system board upside down, with the audio connectors toward you.

78 Chapter 4 Removal and replacement procedures