HP 54501A Service Manual page 86

HP 54501A SERVICE
6-21 . Removal and Installation of System Board Assembly
The effects of ELECTROSTATIC DISCHARGE may damage electronic com-
ponents. Use grounded wriststraps and mats when servicing the System
Board Assembly .
1 .
Disconnect power cable.
2.
Remove the six screws from top and the two screws from each side of
instrument.
3.
Lift top cover off .
4.
Detach line filter cable, W7, from Power Supply Assembly .
5.
Remove do power supply cable, W1 .
6.
Remove the two PCB (printed circuit board) retainers from right front and
rear corner of Power Supply Assembly .
7.
Remove Power Supply Assembly by sliding out through side of instrument.
8.
Disconnect fan cable B1 W1 from System Board Assembly .
9.
Disconnect keyboard cable, W5, and HP-IB Cable, W4, from System Board
Assembly .
10.
Remove rear panel by removing the eight screws securing it to instrument
and lifting off . Refer to previous paragraph Removal and Installation of Rear
Panel , if necessary .
11 .
Carefully place instrument in front-panel-down position or on its side and
remove the EIGHT #10 TORX e screws on the bottom of the instrument that
secure System Board Assembly to cabinet .
12.
Remove the four 5/8 inch nuts holding System Board Assembly BNCs to
front panel.
13 .
Slide System Board Assembly out of cabinet through rear of instrument .
14 .
Replace System Board Assembly by reversing this procedure .