Removal And Replacement Instructions - Tektronix 2205 Service Manual

Attempts to unsolder, remove, and resolder
leads from the component side of a circuit board
may cause damage to the reverse side of the circuit
board.
The following techniques should be used to
replace a component on a circuit board:
1. Touch the vacuum desoidering too! to the
lead at the solder connection. Never place the iron
directly on the circuit board; doing so may damage
the circuit board.
NOTE
Some components are difficult to remove
from the circuit board due to a bend placed in
the component leads during machine in­
sertion. To make removal of machine-
inserted components easier, straighten ■ the
component leads on the reverse side of the
circuit board.
2. When removing
especially an 1C, do not heat adjacent pins con­
secutively. Apply heat to the pins at alternate sides
and ends of the 1C as solder is removed. Allow a
moment for the circuit
proceeding to the next pin.
CAUTION
Excessive heat can cause the etched-ctrcuit
conductors to separate from the circuit
board. Never allow the solder extractor tip to
remain at one place on the circuit board for
more than three seconds. Damage caused by
poor soldering techniques can void the instru-
m m t warranty.
3. Bend the leads of the replacement com­
ponent to fit the holes in the circuit board, if the
component is replaced while the circuit board is
installed in the instrument, cut the leads so they pro­
trude only a small amount through the reverse side
of the circuit board. Excess lead length may cause
shorting to other conductive parts.
4. Insert the leads into the holes of the circuit
board so that the replacement component is
positioned the same as the original component.
Most components should be firmly seated against
the circuit board.
5. Touch the soldering iron to the connection
and apply enough solder to make a firm solder joint.
a multipin component,
board to cool before
Maintenance—2205 Service
Do not move the component while the solder
hardens.
6. Cut off any excess lead protruding through
the circuit board (if not clipped to the correct length
in step 3).
7. Clean the area around the solder connection
with an approved flux-removing solvent. Be careful
not to remove any of the printed information from
the circuit board.
REMOVAL AND REPLACEMENT
INSTRUCTIONS
The exploded view drawings in the Replaceable
Mechanical Parts list (Section 10) may be helpful
during the removal and reinstallation of individual
subassemblies or components. Circuit board and
component locations are shown in the Diagrams
section.
Cabinet
^
a rn in g
To avoid electric shock, disconnect the instru­
ment from the ac-power-lnput source before
removing or replacing any component or
assembly.
To remove the instrument cabinet, perform the
following steps:
1. Disconnect the power cord from the instru­
ment. For instruments with a power-card securing
clamp, remove the Phillips-head screw holding the
power-cord securing clamp before disconnecting
the power cord.
2. Remove two screws and the two power cord
retainers from the rear panel (located on each
side). Remove the rear panel.
3. Remove two screws from the rear panel
(located on each side) and remove it from the
instrument.
4 Remove four screws, one from the left-rear
side and three from the right-rear side of the
cabinet
5. Use one hand to rise the center rear of the
cabinet until the tab clears the slot in the rear
chassis. With the other hand, push the instrument
chassis forward until it clears the cabinet tab.
J |
6-13