Toshiba T4900CT Manual page 43

Procedure 3 Connector Check and Replacement Check
The FDD wiring diagram is shown below.
The 3.5-inch Floppy Disk Drive is connected to the system unit by the FDD cable. This cable
may be disconnected from the system board or may be damaged. Disassemble the T4900CT
following the steps described in Chapter 4, Replacement Procedures, and perform the follow-
ing checks:
Check 1 Make sure the FDD cable is firmly connected to the system board.
If this cable is disconnected, connect it to the lower system board and repeat
Procedure 3. If the FDD is still not functioning properly, perform Check 2.
Check 2 Make sure the two joint connectors (PJ301 and PJ302) are firmly connected to the
upper system board.
If these joint connectors are disconnected, connect them to the upper system
board and repeat Procedure 3. If the FDD is still not functioning properly, per-
form Check 3.
Check 3 The FDD or its cable may be defective or damaged. Replace the FDD with a new
one following the steps in Chapter 4, Replacement Procedures. If the FDD is still
not functioning properly, perform Check 4.
Check 4 The Floppy Disk Controller (FDC) may be defective or damaged. Replace the
lower system board with a new one following the steps in chapter 4, Replacement
Procedures. If the FDD is still not functioning properly, perform Check 5.
Check 5 Replace the upper system board with a new one following the steps in Chapter 4,
Replacement Procedures.
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T4900CT