Repair Of Chip Component Circuit Board - Sony TRINITRON KV-27TW77 Service Manual

KV-27TW77/27TW78
KV-32TW7 W32TW78
2-8. REPAIR OF CHIP COMPONENT CIRCUIT BOARD
2-8-1. POINTS OF COMPONENT REMOVAL SOLDERING
Handing of blower type soldering iron
If hot blast is too strong or applied from a slanting
direction, small components and solder near the
component being removed can be blown off. Do not
use blower type without temperature control. Tweezers
1) Preparation
Soldering iron
2-8-2. NOTES ON SOLDERING FOR CHIP COMPONENTS
1) During soldering a chip component, if a soldering
iron is applied for a long time, the heat may 2) Location
damage the component or cause pattern peeling.
2) Do not reuse a removed component. The
characteristics of such a component may
deteriorate.
3) Use wire solder containing silver (¢ 0.3 or ¢ 0.6).
(The pin electrodes of the laminated chip
capacitor are silver +palladium, so if wire solder
which does not contain silver is used, the silver of
the pin electrode will be sucked into the solder.)
Be careful not to misposition.
LLL LLL LLL LLL
3) Tack soldering and flux application
2-8-3. REMOVAL AND MOUNTING OF COMPONENTS
Chip resistor and chip capacitor
L__)_| Bk
VLEET
REMOVAL
: ree 4) Solderin
* Using two soldering irons
)
° Apply the soldering iron to
1) Mounted state the chip component ahd:
land to heat them and
apply solder.
: Wire solder
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2)Melt the solder.
5) Soldering (Fix the fillet.)
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Pst as
3)Remove the component.
LLL
LIL
6) Visual inspection
Check for the following defects :
LD LED , * No-soldered part |
* Bridge (to other components or lands)
* Mispositioning
* Other defects
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