Keithley 6512, Инструкция по эксплуатации

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Maintenance
7-9
NOTE
In order to avoid damage, assume that all
parts are static sensitive.
1. ICs should be transported and handled only in contain-
ers specially designed to prevent static build-up. Typi-
cally, these parts will be received in anti-static
containers of plastic or foam. Keep these devices in their
original containers until ready for installation.
2. Remove the devices from their protective containers
only at a properly grounded work station. Also, ground
yourself with a suitable wrist strap before handling
parts.
3. Handle the devices only by the body; do not touch the
pins.
4. Any printed circuit board into which the device is to be
inserted must also be grounded to the bench or table.
5. Use only anti-static type de-soldering tools.
6. Use only grounded-tip soldering irons.
7. Once the device is installed on the PC board, it is usually
adequately protected, and normal handling can resume.
7.6 Disassembly instructions
If it is necessary to troubleshoot the instrument or replace a
component, use the following disassembly procedure. An ex-
ploded view of the instrument may be found in Figure 7-5.
WARNING
Disconnect the line cord and any test
leads or cables from the instrument be-
fore disassembly.
1. Remove the top cover as follows:
A. Remove the two screws that secure the top cover to
the rear panel.
B. Grasp the top cover at the rear, and carefully pull up
until the tabs at the front of the cover clear the front
panel. The cover may then be pulled completely
clear.
C. To replace the top cover, reverse the above proce-
dure. Be sure to install the tabs at the front of the
cover before completely installing it.
2. Remove the electrometer board as follows:
A. Remove the four screws that secure the top shield to
the electrometer board.
B. Carefully lift the shield clear of the board.
C. Disconnect the input wires from the electrometer
board.
D. Disconnect the power transformer wires on the elec-
trometer board.
E. Remove the three screws that secure the electrome-
ter board to the standoffs adjacent to the power
transformer.
F. Carefully remove the electrometer board, taking
care not to touch the PC board surfaces or any com-
ponents. When the board is partially removed, dis-
connect the ribbon cable at the mother board end.
3. Remove the mother board as follows:
A. Disconnect the display board ribbon cable near the
front of the instrument.
B. Remove the standoffs, spacers, and screws that se-
cure the mother board to the bottom case. Do not re-
move the three standoffs down the center of the
board.
C. Remove the two screws that secure the rear panel to
the bottom case, and remove the mother board and
rear panel as a single unit.
4. The display board can now be removed as follows:
A. Remove the two screws securing the display board
to the front panel.
B. Disconnect the DIP cable connected to the mother
board.
C. Remove the display board by lifting up and back un-
til the tabs at the bottom of the case are clear and
then lift the display board free.
5. The instrument can be re-assembled by reversing the
above procedure. Make sure that all boards are properly
seated and secured, and that all connections are properly
made. To ensure proper operation, shields must be re-
placed and fastened securely.
WARNING
To ensure continued protection against
safety hazards, power line ground (the
green wire connected to the AC power
receptacle) must be connected to the
rear panel and mother board.