Keithley 2520, Service Manual, Page: 96 / 137

5-6 Disassembly Model 2520 Pulsed Laser Diode Test System Service Manual
Removing power components
The following procedures to remove the power supply and/or power module require that
the case cover and motherboard be removed, as previously explained.
Power supply module removal
Perform the following steps to remove the power supply module:
1. Disconnect the wires that connect the power supply module on the bottom of the
chassis to the rear panel power module.
2. Remove the screws that secure the power supply to the chassis bottom, then
remove the module.
Power module removal
Perform the following steps to remove the rear panel power module:
1. Disconnect the power module's ground wire. This green and yellow wire connects
to a threaded stud on the chassis with a kep nut.
2. Squeeze the latches on either side of the power module while pushing the module
from the access hole.
Instrument re-assembly
Re-assemble the instrument by reversing the previous disassembly procedures. Make sure
that all parts are properly seated and secured, and that all connections are properly made.
WARNING To ensure continued protection against electrical shock, verify that
power line ground (green and yellow wire attached to the power mod-
ule) is connected to the chassis. Also make sure the ground wires are
attached to the power transformer mounting screws.
Also ensure the six bottom case screws are properly installed to secure
and ground the case cover to the chassis.