Keithley 2700, Service Manual

Page: 104 / 174

5-6 Disassembly
Front panel disassembly
Use the following procedures to remove the display board and/or the pushbutton switch pad:
NOTE You must first remove the case cover, the front/rear input switch, and the front input
terminal wires as described earlier in this section.
1. Unplug the display board ribbon cable from connector J1014.
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 sepa-
rates from the chassis.
3. Using a thin-bladed screwdriver, pry the plastic PC board stop (located at the bottom of
the display board) until the bar separates from the casing. Pull the display board from
the front panel.
4. Remove the switch pad by pulling it from the front panel.
Removing power components
The following procedures to remove the power transformer and/or power module require
that the case cover and motherboard be removed, as previously explained.
Power transformer removal
Perform the following steps to remove the power transformer:
1. Remove the motherboard
2. Remove the two nuts that secure the transformer to the side of the chassis.
3. Pull the black ground wire off the threaded stud and remove the power transformer
from the chassis.
Power module removal
Perform the following steps to remove the power module:
1. Remove the motherboard.
2. Remove the POWER switch rod.
3. Remove the card cage (see “Card cage removal” above).
4. Disconnect the power module’s ground wire. This green and yellow wire connects to a
threaded stud on the chassis with a kep nut.
5. Squeeze the latches on either side of the power module while pushing the module from
the access hole.