Texas Instruments Extensa 660 Series Maintenance Manual page 83

6
Keyboard FPC Cable
O.K.?
Yes
Checked Keyboard
Interrupt?
Yes
Checked Keyboard
Scanning Signals?
Yes
Check U8 Entire Circuit
END
Figure 5-7 Keyboard Interface Troubleshooting Diagram
System fils to boot:
Keyboard Interface Checks
Check FPC Cable:
No
Broken or not
Check U8(M38813)
Pin15, IRQ1
No
Check CN18
PIN 1 ~ PIN 15 (X1~15)
No
Check CN16
PIN 1 ~ PIN 8 (Y0~7)
Troubleshooting Procedures 5-23