Tektronix TM 503 User Manual

System Maintenance—TM 503
interconnecting Pins. To replace a pin which is mounted
on a circuit board, first disconnect any pin connectors.
Then,
unsolder the damaged pin and pull it out of the
board with a pair of pliers. Be careful not to damage the
wiring on the board with too much heat. Ream out the hole
in the circuit board with a 0.031-inch drill. Remove the
ferrule from the new interconnecting pin and press the new
pin into the hole in the circuit board. Position the pin in
the same manner as the old pin. If the old pin was bent at
an angle to mate with a connector, bend the new pin to
match the associated pins.
NOTE
A pin replacement kit including necessary tools,
instructions, and replacement pins is available from
Tektronix, inc. Order TEKTRONIX Part No.
040-0542-00.
Cam Switches. Repair of cam-type switches should be
undertaken only by experienced maintenance personnel.
Switch alignment and spring tension of the contacts must
be carefully maintained for proper operation of the switch.
For assistance, contact your local TEKTRONIX Field
Office or representative.
NOTE
A cam-type switch repair kit including necessary
tools, instructions, and replacement contacts is avail-
able from Tektronix, Inc. Order TEKTRONIX Part
No, 040-054 1-00.
The cam-type switches consist of rotating cam drums
which are turned by front-panel knobs, and sets of
spring-leaf contacts mounted on adjacent circuit boards.
The contacts are actuated by lobes on the cams. These
switches can be disassembled for inspection, cleaning,
repair, or replacement as follows:
1. Remove the screws which hold the metal cover on the
switch, and lift the cover off the switch. The switch is now
open for inspection or cleaning.
2. To completely remove a switch from the circuit
board, first remove any knobs or shaft extensions. Loosen
the coupling at the potentiometer at the rear of the switch,
and pull the long shaft out of the switch assembly.
3. Remove the screws (from the opposite side of the
circuit board} which hold the cam drum to the board,
4. To remove the cam drum from the front support
block, remove the retaining ring from the shaft on the front
of the switch and slide the cam drum out of the support
block. Be careful not to lose the small detent roller.
5. To replace defective switch contacts, follow the
instructions given in the switch repair kit.
6. To re-install the switch assembly, reverse the above
procedure.
Pushbutton Switches. The pushbutton switches are not
repairable and should be replaced as a unit if defective. Use
a suction-type de-soldering tool to remove solder from the
circuit board when removing these switches.
incandescent Bulbs. Most of these light bulbs are
mounted on the sub-panel using plastic sleeve stand-offs.
Unsolder the lead wires and pull the bulb out of the sleeve
from the rear of the sub-panel.
Light-Emitting Diodes. LED’s used as indicators are
mounted on the sub-panels with plastic sleeve sockets
similar to the incandescent bulb mountings or they are
soldered directly to a sub-assembly and so mounted that
they protrude through holes in the panel. fn these cases, the
sub-assembly must be exposed and the anode and cathode
lead orientations carefully noted before unsoldering the
defective LED. See Figure 3 for LED lead identifying
information.
Red-dot, cathode
Anode
Short bulb
Long bulb
Top of character
Decimal point
Bent leads
Cathode
Seven-segment character chip
Figure 3. Light-emitting diode (LED) lead orientation illustration.
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Tektronix TM 503 Specifications

General

Brand	Tektronix
Model	TM 503
Category	Control Unit
Language	English