Panasonic KX-FT21BX, Service Manual

Page: 51 / 206

TROUBLESHOOTING GUIDE
- 25 -
KX-FT21LA
Power on.
Check LCD.
Plug in the AC cord.
slightly changes
good
No
Yes
Blank
AC
12:00AM
or
LCD
LCD LCD
Already known symptom
Determine the symptom using
the check list. (See page 25.) See the table for
troubleshooting items.
See the digital board
section.
(See page 59.)
See the digital board
section.
(See page 59.)
Blank LCD means that the power line
is broken (open-circuit).
Blinking
3. TROUBLESHOOTING DETAILS
3-1. OUTLINE
Troubleshooting guide provides a logical path of deduction to assist in locating a fault and suggests methods
of restoring the unit to full working condition. Use the reported symptoms of the fault to determine the best
troubleshooting method. Even difficult faults can be tracked to a specific block or area, for example, the "Digital
Board" or "Image Sensor".
A variety of fault descriptions from customers often point to the same area and, for this reason, careful analysis of
the reported symptoms is required. After every repair, test all functions to ensure no problems are evident.
3-2. STARTING TROUBLESHOOTING
Select the appropriate troubleshooting method according to the symptoms.