Panasonic KX-TGA840FXN, Service Manual

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KX-TG8421HGN/KX-TGA840FXN
12.3. How to Replace the Flat Package IC
Even if you 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.
12.3.1. Preparation
• PbF (: Pb free) Solder
• Soldering Iron
Tip Temperature of 700 ° 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)
12.3.2. How to Remove the IC
1. Put plenty of solder on the IC pins so that the pins can be completely covered.
Note:
If the 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 board 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.