8 Trouble Shooting
8-6
SAM4S ER-650 SERIES
8-6 Key Board Problem
End
Key Board Problem
Key Input
Failure ?
Y
N
1. Check Decoder HC138(U7) & Key Board
CS Signal
2. Check HC138(U24,U25)
3. Check HCT541 & Data Line
4. Check the related circuit
5. Check & Change Key Board Ass’y
6. Check the KBD Connector on PBA
Specific Key
Failure?
1. Check the affected Key
2. Check the Matrix Bus & Data Bus
3. Check the Diodes(D13~D28)
4. Check the Key Board Ass’y
N
Mode Key
Ok?
Y
Y
1. Check the Harness & Mode Key Ass’y
2. Check Diode (D23)
3. Check the HCT541 & Data Bus
N
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Summary of Contents for ER-650
Page 2: ...All manuals and user guides at all guides com...
Page 68: ...9 Block Diagram 9 2 SAM4S ER 650 SERIES Memo All manuals and user guides at all guides com...
Page 70: ...10 Wiring Diagram 10 2 SAM4S ER 650 SERIES Memo All manuals and user guides at all guides com...
Page 73: ...SAM4S ER 650 SERIES 11 3 11 2 MEMORY PART All manuals and user guides at all guides com...
Page 75: ...SAM4S ER 650 SERIES 11 5 11 4 FISCAL PART All manuals and user guides at all guides com...
Page 78: ...11 8 SAM4S ER 650 SERIES 11 7 KEY SCAN PART Y All manuals and user guides at all guides com...
Page 79: ...SAM4S ER 650 SERIES 11 9 11 8 LCD DISPLAY PART All manuals and user guides at all guides com...
Page 80: ...11 10 SAM4S ER 650 SERIES 11 9 PRINTER PART G G All manuals and user guides at all guides com...
Page 86: ...All manuals and user guides at all guides com a l l g u i d e s c o m...