Panasonic KX-TG1843ALS, Service Manual

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23 HOW TO REPLACE THE FLAT PACKAGE IC
Even ifyou do not have the special tools (for example, a spot heater) to remove the Flat IC, with some solder (large amount),
a soldering iron and a cutter knife, you can easily remove the ICs that have more than 100 pins.
23.1. PREPARATION
•
• •
•
PbF (: Pb free) Solder
• • • •
Soldering Iron
Tip Temperature of700°F ± 20°F (370°C ± 10°C)
Note: We recommend a 30 to 40 Watt soldering iron. An expert may be able to use a 60 to 80 Watt iron where someone with
less experience could overheat and damage the PCB foil.
•
• •
•
Flux
Recommended Flux: Specific Gravity
→
0.82.
Type
→
RMA (lower residue, non-cleaning type)
Note: See ABOUT LEAD FREE SOLDER (PbF: Pb free) (P.4).
23.2. FLAT PACKAGE IC REMOVAL PROCEDURE
1. Put plenty ofsolder on the IC pins so that the pins can be completely covered.
Note:
Ifthe IC pins are not soldered enough, you may give pressure to the P.C. board when cutting the pins with a cutter.
2. Make a few cuts into the joint (between the IC and its pins) first and then cut off the pins thoroughly.
3. While the solder melts, remove it together with the IC pins.
When you attach a new IC to the board, remove all solder left on the land with some tools like a soldering wire. If some solder is
left at the joint on the board, the new IC will not be attached properly.
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KX-TG1843ALS / KX-TGA122AZS / KX-TGA121AZS