Tektronix 7623, Instruction Manual

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Maintenance-7623/R7623 Service
B. CIRCUIT BOARD PIN SOCKETS.
The pin sockets on the circuit boards are soldered to the
rear of the board. To replace one of these sockets, first
unsolder the pin (use a vacuum-type desoldering tool to
remove excess solder). Then straighten the tabs on the
socket and remove it from the hole in the circuit board.
Place the new socket in the circuit board hole and press the
tabs down against the board. Solder the tabs of the socket
to the circuit board; be careful not to get solder into the
socket.
NOTE
The spring tension of the pin sockets ensures a good
connection between the circuit board and the pin.
This spring tension can be destroyed by using the pin
sockets as a connecting point for spring-loaded probe
tips, alligator dips, etc.
2. Remove the CRT base socket from the rear of the
CRT.
3. Loosen the two screws located on each side of the
CRT socket until the tension of the springs on these screws
is released. Then, press in on the screws to be sure that the
CRT clamp is loose.
4. Disconnect the deflection plate connectors. Be care
ful not to bend these pins.
5. Disconnect the CRT anode plug from the jack
located on the front of the high-voltage compartment.
Ground this lead to the chassis to dissipate any stored
charge.
C. END-LEAD PIN CONNECTORS.
The pin connectors used to connect the wires to the
interconnecting pins are clamped to the ends of the
associated leads. To replace damaged end-lead pin
connectors, remove the old pin connector from the end of
the lead and clamp the replacement connector to the lead.
Some of the pin connectors are grouped together and
mounted in a plastic holder; the overall result is that these
connectors are removed and installed as a multi pin
connector. To provide correct orientation of this multi pin
connector when it is replaced, an arrow is stamped on the
circuit board and a matching arrow is molded into the
plastic housing of the multi-pin connector. Be sure these
arrows are aligned as the multi-pin connector is replaced. If
the individual end lead pin connectors are removed from
the plastic holder, note the color of the individual wires for
replacement.
Cathode-Ray Tube Replacement. To replace the
cathode-ray tube, proceed as follows:
WARNING
li
Use care when handling a CRT. Protective clothing
and safety glasses should be worn. Avoid striking it
on any object which might cause it to crack or
implode. When storing a CR T, place it in a protective
carton or set it face down in a protected location on a
smooth surface with a soft mat under the faceplate to
protect it from scratches.
6. Remove the two screws securing the CRT bezel to
the front panel. Remove the plastic faceplate protector and
light filter.
7. Hold one hand on the CRT faceplate and push
forward on the CRT base with the other. As the CRT starts
out of the shield, grasp it firmly. Guide the anode lead
through the cutout in the CRT shield as the CRT is
removed.
B. REPLACEMENT.
1. Loosen clamp blocks located at each corner of CRT
shield. Insert the CRT into the shield. Guide the anode lead
through the hole in the CRT shield.
2. Clean the CRT faceplate, plastic faceplate protector,
and the light filter with denatured.alcohol.
3. Re install the CRT bezel, faceplate protector, and
light filter. Firmly tighten the two screws.
4. Push forward on the CRT base to be certain that the
CRT is as far forward as possible. Then tighten the two
screws beside the CRT base until the springs on the screws
are fully compressed.
5. Reposition and tighten down clamp blocks to hold
the faceplate of the CRT tightly against the implosion
shield. The clamps are located at each corner of the CRT
shield.
A. REMOVAL.
1. Remove the heat radiator/Low-Voltage Regulator
circuit board assembly as described previously.
6. Replace the CRT base socket.
7. Reconnect the CRT anode plug.
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