Component Replacement - Tektronix Type Z Instruction Manual

PREVENT VE MA NTENANCE
The Z Unit is a stable instrument, and will require com ­
plete calibration very infrequently. However, to be certain
that the unit is operating properly at all times, the cali ­
bration of the unit should be checked after each 500-hour
period of operation (or every six months if the unit is used
intermittently). A complete step-by-step procedure for cali ­
brating the unit and checking its operation is given in the
Calibration section of this manual.
Visual nspection
Many potential and existent troubles can be detected by
a visual inspection of the unit. For this reason, a complete
visual check should be performed every time the unit is
inoperative, needs repairs, or needs recalibration. Apparent
defects may include loose or broken connections, damaged
connectors, improperly seated tubes or transistors, scorched
or burned parts, and broken terminal strips. The remedy
for these troubles is readily apparent except in the case
of heat-damaged parts. Damage to parts due to heat is
often the result of other less apparent troubles in the unit.
It is essential that the cause of overheating be found before
replacing the damaged parts.

COMPONENT REPLACEMENT

General
Useful information concerning the replacement of im­
portant parts in the Z Unit is given in this portion of the
manual. Because of its precision design, replacement of
close tolerance components will require calibration of the
unit to assure proper operation. Refer to the Calibration
section of this manual for a complete procedure.
steps in the procedure are to be performed out of sequence
to get the repaired portion of the Z Unit calibrated, refer
to the preceding portion of the procedure for more in f or-
mation about control panel settings and test equipment
used.
Switches
If a switch is found to be defective and needs to be
repaired or replaced, use normal care in unsoldering and
MA NTENANCE
disconnecting leads from the terminals. To remove some
switches, such as the AC-DC, Polarity, and Range, the
front overlay panel must be removed first to obtain access
to the switch mounting screws.
ingle wafers on wafer-type switches are not normally
replaced. If a wafer is defective, the entire switch should
be replaced. ome switches may be ordered from the
factory either unwired or with parts wired in place, as de­
sired. Refer to the Parts List to find the wired and unwired
part numbers.
When soldering the leads to a wafer-type switch, do not
let solder flow around and beyond the rivet on the switch
terminal. Otherwise the spring tension of the switch con ­
tact may be destroyed.
Turret Attenuators
To remove or to replace a component inside one of the
VOLT /CM turret attenuators, the following instructions are
given:
1. To remove the turret, loosen the 0.050" alien set screw
(see Fig. 4-1). Grasp the knob and pull it outward far
enough to let the shaft free the turret. Do not pull the
shaft too far out or it will not hold the detent wheel in
position.
2. Remove the turret. Remove the end caps from the body
of the turret to obtain access to the components.
When replacing any of the components inside the
turret, the lead lengths and parts placement are
critical. Duplicate the original lead lengths and
the exact part placement. Use parts ordered from
the factory to assure correct physical size and
tolerance accuracy. Do not use excessive heat or
If the
let the soldering iron touch the white plastic part
of the turret body. No attempt should be made
to replace button capacitors C413E, C414E, or
C415E. These parts are sweat-soldered in the
outer metal
grounding path.
of the turret before the inside components are
soldered into place. It is extremely unlikely that
these capacitors will
ever, if a button capacitor needs to be replaced,
order a replacement wired turret body from the
factory.
ON 4
NOTE
ring to secure a low inductance
The ring is fitted to the body
become defective. How ­
4-1