TROUBLESHOOTING GUIDE
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KX-FT21LA
cold soldering
LEADED PARTS
(section)
cold soldering
SMT PARTS
cold soldering
RESISTOR ARRAY
cold soldering
CHIP PARTS (section)
solder ball
SMT PARTS
SMT PARTS
solder waste
3-7. Digital board section
One of most difficult problems to deal with is when the system will not boot up.
The symptom: No response when the power is turned on. (No LCD display, keys are not accepted.)
Then first thing to do is check the power source, If there is no problem with the power supply unit, then there is a problem with
the digital unit (main board).
As there are many potential causes in this case (ASIC, etc.), it may be difficult to specify what you should check first. If a mistake
is made in the order of checks, a normal part may be determined faulty, wasting both time and money.
Although the tendency is to regard the problem as a serious one (IC malfunction, etc.), usually most cases are caused by
solder faults (poor contact due to a tunnel in the solder, signal short circuit due to solder waste).
Note:
1. Electrical continuity may have existed at the factory check, but a faulty contact occurred as
a result of vibration, etc., during transport.
2. Solder waste remaining on the board may get caught under the IC during transport, causing a
short circuit.
Содержание KX-FT21BX
Страница 14: ... 14 Model KX FT21BX KX FT21BX W KX FT21BX KX FT21BX W MEMO ...
Страница 26: ... 26 Model KX FT21BX KX FT21BX W KX FT21BX KX FT21BX W YM Q KXFT21BX KXFT21BX W Printed in Japan ...
Страница 36: ...KX FT21LA 10 CCITT NO 1 TEST CHART Actual size ...
Страница 97: ...TROUBLESHOOTING GUIDE 71 KX FT21LA MEMO ...
Страница 117: ...TROUBLESHOOTING GUIDE 91 KX FT21LA 6 1 PRINTOUT EXAMPLE ...
Страница 118: ...KX FT21LA 92 ADJUSTMENTS Page 1 Adjusting the Feeder Pressure 93 ...
Страница 178: ...KX FT21LA 152 MEMO ...
Страница 192: ...KX FT21LA 166 FIXTURES AND TOOLS EC8 EC5 EC7 EC3 EC1 EC2 EC2 EC4 EC6 ...
Страница 197: ... 171 KX FT21LA B A C XSB4 6 XTW3 S10P XSN3 W6FZ Part No Illustration 5 ACTUAL SIZE OF SCREWS AND WASHER ...
Страница 198: ...KX FT21LA 172 A6 P2 A7 P3 A4 A1 P4 P5 P1 A5 A3 A2 ACCESSORIES AND PACKING MATERIALS ...
Страница 206: ...KX FT21LA 180 D Q KXFT21LA Printed in Japan ...