Removal And Replacement Instructions - Tektronix 2246 1Y Service Manual

Maintenance—2246 1Y and 2246 Mod A Service
the solder connection
removing solvent (such as isopropyl alcohol) and
allow it to air dry.
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Only an experienced maintenance person,
proficient in the use of vacuum-type de­
soldering equipment should attempt repair of
any circuit board in this instrument. Many in­
tegrated circuits are static sensitive and may
be damaged by solder extractors that gen­
erate static charges. Perform work involving
static-sensitive devices only at a static-free
work station white wearing a grounded anti­
static wrist strap. Use only an antistatic
vacuum-type solder extractor approved by a
Tektronix Service Center.
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£ CAUTION |
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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 desoldering tool tip to the
lead at the solder connection. Never place the
tip directly on the board; doing so may damage
the 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
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 board to cool
before proceeding to the next pin.
6-38
with an approved flux-
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removal of machine-
a multipin component,
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Excessive heat can cause the etched circuit
conductors to separate
board. Never allow the solder extractor tip to
remain at one place on the board for more
than three seconds. Solder wick, spring-
actuated or squeeze-bulb solder suckers,
and heat blocks (for desoldering multipin
components) must not be used. Damage
caused by poor soldering techniques can void
the instrument warranty.
3. Bend the leads of the replacement component
to fit the holes in the circuit board. If the com­
ponent is replaced while the board is installed in
the instrument, cut the leads so they protrude
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 board so
that the replacement component is positioned
the same as the original component. Most com­
ponents should be firmly seated against the
circuit board.
5. Touch the soldering iron tip to the connection
and apply enough solder to make a firm solder
joint. 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 infor­
mation from the circuit board.
REMOVAL AND REPLACEMENT
INSTRUCTIONS
WARNING I
To avoid electric shock, disconnect the instru­
ment from the power input source before
removing or replacing any component or
assembly.
The exploded view drawings
Mechanical Parts list may be helpful during removal
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from the circuit
in Replaceable