Toshiba TECRA S1 - Manual (Page 61)

2 Troubleshooting 2.7 Keyboard
2-24 TECRA S1 Maintenance Manual
Check 3 The System board may be faulty. Replace it with a new one following the
instructions in Chapter 4. If the keyboard is still not functioning properly,
perform Check 4.
Check 4 The memory may be defective. Replace the memory module with a new one
following the steps described in Chapter 4. If the problem persist, perform
Check 5.
Check 5
The CPU may be faulty. Disassemble the computer following the steps
described in Chapter 4 and replace the CPU with a new one.