Panasonic KX-FT21BX Service Manual page 95

NG Example
1.
5V or 3.3V
0V
2.
3.
ASIC
Short circuit from the adjacent signal wires.
Check for a short circuit in the RA and IC leads and the signal wire
at the through hole.
Short between the signal line and GND.
Approx. 0 or 1 V
0V
RA SRAM
Solder fault on RA.
Solder waste
470
Through hole
OR IC malfunction
IC1
- 69 -
KX-FT21LA
Solder ball
IC3
Chip