Component Removal And Replacement - Tektronix 213 DMM Instruction Manual

has been connected to the power line with the
power-line filter plug (P420) disconnected
from the battery charger, C417 and C418 will
remain charged until P420 is connected to the
charger or discharged by the grounding method.
E3
Some of the circuit boards in this instrument
are multi-layer type boards with conductive ·
paths laminated between the top and bottom
board layers. All soldering on these boards
should be done with extreme care to prevent
breaking the interconnections between the
layers. Only experienced maintenance per-
sonnel should attempt repair of these boards.
The-reliability and accuracy of this instrument can be main-
tained only if proper soldering techniques are used when re-
pairing or replacing parts. General soldering techniques that
A1
ATTENUATOR
BOARD
A3 AID
CONVERTER
BOARD
HOLD-DOWN NUTS*
A6
SECONDARY
POWER SUPPLY
BOARD
(INSIDE COVER)
A4
AMPLIFIER
BOARD
Maintenance-213 Service
apply to maintenance of any precision electronic equipment
should be used when working on this instrument. Ordinary
60/40 rosin-core electronic-grade solder and a 15-watt solder-
ing iron is adequate for most soldering in the 213. Should
a larger wattage soldering iron be required on some of the
metal shields or larger common connection circuit pads, use
a 35-watt or 40-watt pencil-type soldering iron.
After soldering is completed, clean the area around the solder
connection with isopropyl or ethyl alcohol. Be careful not
to remove any information printed in the area.
Component Removal and Replacement
Since component removal and replacement requires instru-
ment disassembly, replacement procedures for the batteries,
crt, and circuit boards will be explained first. These replace-
ment procedures are written so that in most cases, each pre-
ceding component must be removed before the following
component is removed (e.g. the batteries must be removed
before the A/0 Converter Board is removed). The location
of each circuit board is shown in Figure 4-2.
*NOTE: A4 Amplifier Board hold-down nuts are in
same location on bottom side of the instru-
ment.
1481-1
Figure 4-2. Circuit board locator.
@
4-3