Panasonic KX-FLM551, Service Manual

Page: 94 / 319

Accordingly, the problem presented here is whether each IC outputs the correct signal. (See the
I/O direction diagram on the next page.) In other words, is it constantly switching between 3.3 V
(H) and 0 V (L) as described earlier.
Note:
All you have to do is check that the IC repeatedly outputs (H) 3.3 V
and (L) 0 V.
After the power is turned on, the ASIC initializes and checks each IC.
The ROM, SDRAM, and modem are checked.
If initialization fails for the ICs , the system will not boot up.
In this case, please find the cause as follows.
CROSS REFERENCE:
NG EXAMPLE ()
CHECK THE STATUS OF THE DIGITAL BOARD ()
POWER SUPPLY BOARD SECTION ()
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