Panasonic KX-FB423RU-W Service Manual ▷ View online
7.5.8. INITIALIZING ERROR
After the power is turned on, the ASIC initializes and checks each IC.
The ROM, DRAM, 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:
CHECK THE STATUS OF THE DIGITAL BOARD (P.104)
POWER SUPPLY BOARD SECTION (P.118)
NG EXAMPLE (P.160)
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CROSS REFERENCE:
CHECK THE STATUS OF THE DIGITAL BOARD (P.104)
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7.5.9.
ANALOG BOARD SECTION
This chapter provides the testing procedures required for the analog parts. A signal route to be tested is determined depending
upon purposes. For example, the handset TX route begins at the handset microphone and the signal is output to the telephone
line. The signal mainly flowing on this route is analog. You can trace the signal with an oscilloscope. The signal flow on each
route is shown in the Check Sheet here. If you find a specific problem in the unit, for example if you cannot communicate with
the H/S, trace that signal route locally with the following Check Sheet and locate the faulty point.
upon purposes. For example, the handset TX route begins at the handset microphone and the signal is output to the telephone
line. The signal mainly flowing on this route is analog. You can trace the signal with an oscilloscope. The signal flow on each
route is shown in the Check Sheet here. If you find a specific problem in the unit, for example if you cannot communicate with
the H/S, trace that signal route locally with the following Check Sheet and locate the faulty point.
7.5.9.1. CHECK SHEET
Note: { }: Inside the digital board
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3. No ring tone (or No bell)
CROSS REFERENCE:
CHECK SHEET (P.107)
NCU SECTION (P.167)
4. No tone dialing
CROSS REFERENCE:
CHECK SHEET (P.107)
7.5.9.2. DEFECTIVE ITS (Integrated Telephone System) SECTION
1. No handset and speakerphone transmission / reception
Perform a signal test in the ITS or the NCU section and locate a defective point (where the signal disappears) on each route
between the handset microphone and telephone line (sending), or between the telephone line and the handset speaker
(receiving), or between the microphone and the telephone line (sending), or between the telephone line and the speaker
(receiving). Check the components at that point. CHECK SHEET(P.107) is useful for this investigation.
between the handset microphone and telephone line (sending), or between the telephone line and the handset speaker
(receiving), or between the microphone and the telephone line (sending), or between the telephone line and the speaker
(receiving). Check the components at that point. CHECK SHEET(P.107) is useful for this investigation.
2. No pulse dialing
CROSS REFERENCE:
NCU SECTION (P.167)
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