Tektronix 7623, Instruction Manual

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Maintenance — 7623/R7623 Service
1. Remove the securing screws.
2. Pull out on the edges of the board until the board
clears the interconnecting terminals. Hold the board parallel
to the Main Interface board until the board is free, so as not
to bend the interconnecting terminals.
3. To replace the circuit board, position it so the
interconnecting pins and sockets mate properly.
4. Gently press the circuit board against the mounting
surface. Be sure that all the interconnecting pins and
sockets mate properly.
5. Replace the securing screws.
C. LOGIC CIRCUIT BOARD REPLACEMENT.
1. Slide out the power unit as described previously.
2. Disengage the plastic snaps which secure the sides of
the board.
3. Pull out on the edges of the board until the board
clears the interconnecting terminals. Hold the board parallel
to the Main Interface board until the board is free, so as not
to bend the interconnecting terminals.
4. To replace the Logic board, position it so the guide
holes in the board mate with the guide posts. Check that all
the interconnecting pins and sockets mate properly.
5. Gently press the board against the Main Interface
board until the plastic snaps secure the board.
D. MAIN INTERFACE CIRCUIT BOARD
REPLACEMENT.
1. Slide out the power unit as described previously.
2. Remove all of the plug on circuit boards from the
Main Interface board (remove plug-in units to gain access to
plug-on boards on front of Main Interface board).
3. Disconnect the multi-pin connectors from the rear of
the Main Interface board. Note the order of these connec­
tors so they can be correctly replaced.
4. Remove the three screws from inside each plug-in
compartment which hold the plug in interface connectors
to the chassis (total of nine screws). Also remove the
hexagonal posts which secure the ground straps to the Main
Interface board.
5. Remove the Main Interface board assembly through
the rear of the instrument.
6. To replace the Main Interface board, reverse the
order of removal. Match the arrows on the multi-pin
connectors to the arrows on the board. Correct location of
the pin connectors is shown in the circuit board illustration
in the Diagrams section.
E. LOW-VOLTAGE REGULATOR CIRCUIT BOARD
REPLACEMENT.
1. Remove the four screws which secure the heat
radiator to the rear frame of the instrument.
2. Slide the heat radiator out of the rear of the
instrument and disconnect the pin connectors. Remove the
heat radiator from the instrument.
3. Remove the four screws which secure the plastic
protective cover to the heat radiator.
4. Remove the power transistors from the back of the
heat radiator. Note the location of each power transistor.
5. To replace the Low-Voltage Regulator board, reverse
the order of removal.
NOTE
After replacing the power transistors, check that the
transistor cases are not shorted to the heat radiator
before applying power.
F. RECTIFIER BOARD REPLACEMENT.
To replace the Rectifier board, proceed as follows:
1. Slide out the power unit as described previously.
2. Disconnect the pin connectors from the board.
3. Disconnect the wires soldered to the top of the
board .
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