Keithley 2001 Repair Manual

Disassembly
3-3
side of the chassis. Each ear is marked ÒRIGHTÓ or
ÒLEFTÓ on its inside surface.
3. Remove Rear Bezel  The rear bezel is secured to
the chassis by two captive screws. To remove the
rear bezel, loosen the two screws and pull the bezel
away from the case.
4. Remove Grounding Screw  Remove the
grounding screw for the case cover. This screw is
located on the bottom side of the instrument at the
rear.
5. Remove Chassis  Grasp the front bezel of the in-
strument and carefully slide the chassis forward,
out of the metal case.
The internal pc-board assemblies are now accessible.
3.4.2 Analog board top shield removal
Most of the analog circuitry is located under the top
shield for the analog board. The top shield (shown in
drawing 2001-050) is secured to the analog board by a
single screw. To remove the top shield, simply loosen
the screw and carefully lift the shield out of the chassis.
3.5 PC-boards removal
There are three pc-boards mounted in the chassis; the
digital board, the A/D converter board and the analog
board. The removal of these three boards are covered in
this paragraph. The display board is mounted in the
front panel assembly. The removal of the display board
is covered in paragraph 3.6.
Any pc-board can be removed without having to re-
move any of the other boards. Note that the A/D con-
verter board plugs into the analog board and can be left
installed when removing the analog board.
NOTE
Before performing any of the follow-
ing procedures to remove a pc-board,
remove the case cover as explained in
paragraph 3.4.1.
3.5.1 Digital board
The digital board is removed through the bottom of the
chassis (see drawing 2001-053). Note that the power
switch pushrod does not have to be removed in order
to remove the digital board.
Perform the following steps to remove the digital
board:
1. Unplug Cables  Turn the chassis upside-down
and unplug the following cables from the digital
board:
A. Unplug the display board ribbon cable from
connector J1033.
B. Unplug the transformer cable from connector
J1032.
C. Unplug the analog board ribbon cable from
connector J1027. This cable connection is locat-
ed under the power switch pushrod.
D. Unplug the fan cable from connector J1037.
This two conductor cable connection is located
at the rear of the digital board in front of the
IEEE connector.
2. Unfasten PC-Board  Remove the following
screws and nuts to unfasten the digital board from
the chassis:
A. At the rear panel, remove the two nuts that se-
cure the IEEE connector to the chassis.
B. Remove the screw that connects ground of the
+5V regulator (U629) to the chassis. The regu-
lator is located at the front of the digital board
behind the large electrolytic capacitor (C611).
C. Remove the four screws that secure the digital
board to the chassis. One screw is located at the
rear of the digital board in front of the bank of
12 capacitors. Another screw is located next to
the +5V regulator (U629). The other two screws
are located near the connector for the scanner
card.
3. Remove Digital Board  The board is held in place
by edge guides on each side. Slide the digital board
forward until the board edges clear the guides, and
then carefully pull the board out of the chassis.
3.5.2 A/D converter board
The A/D converter board is located under the analog
board top shield (see drawing 2001-050).

Keithley 2001 Specifications

General

Brand	Keithley
Model	2001
Category	Multimeter
Language	English