Keithley 2500, Service Manual

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5-6 Disassembly Model 2500 Service Manual
Front panel disassembly
Use the following procedure to remove the display board and/or the pushbutton switch
pad.
1. Remove the power switch rod. Carefully disconnect the power switch rod from the
power switch mounted on the rear panel power module. Slide the rod toward the
rear until it clears the access hole in the front panel, then remove the rod.
2. Remove the front panel assembly. This assembly has four retaining clips that snap
onto the chassis over four pem nut studs. Two retaining clips are located on each
side of the front panel. Pull the retaining clips outward and, at the same time, pull
the front panel assembly forward until it separates from the chassis.
3. Unplug the display board ribbon cables.
4. Using a thin-bladed screw driver, pry the plastic PC board stop (located at the bot-
tom of the display board) until the bar separates from the casing. Pull the display
board from the front panel.
5. Remove the switch pad by pulling it from the front panel.
Removing power components
The following procedures to remove the power supply and/or power module require that
the case cover and mother board be removed, as previously explained.
Power supply module removal
Perform the following steps to remove the power supply module:
1. Disconnect and remove the cables that connect the power supply module on the
bottom of the chassis to the power transformer and 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.