HP 9020 Service Manual page 135

Assembly Access
4-35
Keyswitch Board/Keyboard Electronics Board
To remove the keyboard and separate the keyswitch board from the keyboard electronics board,
proceed as follows:
1. UNPLUG COMPUTER POWER CORD FROM AC OUTLET.
2. Remove keyboard from computer as previously described. The keyboard consists of keys-
witch board and keyboard electronics board.
3. Place keyboard upside down (keycaps down) on an antistatic surface (Figure 4-33).
4. Unplug keyboard electronics board cable from keyswitch board (Figure 4-33).
5. Remove seven # 1 Pozidriv screws that interconnect keyswitch board and keyboard electro-
nics board (Figure 4-33).
6. Lift keyboard electronics board off keyswitch board.
RTC/NVM BATTERY INTERCONNECTING LANGUAGE
ASSEMBLY CABLE RESISTORS
KEYBOARD
ELECTRONICS BOARD
Keyswitches
* *
*
#1 POZIDRIV SCREW
KEYSWITCH
BOARD
Figure 4-33. Disassembling Keyboard
1. UNPLUG COMPUTER POWER CORD FROM AC OUTLET.
*
2. Remove keyboard from computer as previously described and place on antistatic surface.
3. Remove keycap from defective keyswitch.
4. Remove keyboard electronics board from keyswitch board as previously described.
5. Unsolder the defective switch from the keyswitch board (four solder joints per switch).
6. Press in on the two tabs that hold the keyswitch in place and pull the switch up and out of the
switch mounting plate.
Reassembly Note
Ensure that the replacement keyswitch is the proper type. Install the
replacement keyswitch with the proper orientation and solder the switch
leads.