HP 9020 Service Manual page 177

3. Remove two #2 Pozidriv screws from right side of chassis (Figure 4-80).
4. Loosen three thumbscrews at right side of chassis (Figure 4-80).
THUMBSCREWS
Figure 4-80. Releasing Display Power Supply Board
Assembly Access
4-77
DISPLAY
POWER SUPPLY
BOARD
#2 POZIDRIV
SCREWS