Fdd Interface Check - Texas Instruments Extensa 660 Series Maintenance Manual

4
BIOS Menu
Setup
O.K.?
Yes
Floppy Diskette
properly formatted?
Yes
FDD Power Checked?
Yes
FDD Motor Checked?
Yes
Seek Operation Checked?
Yes
Check Read or Write
Operation
Yes
END
Figure 5-5 FDD Interface Troubleshooting Diagram
System Fails to Boot:

FDD Interface Check

No Enter Correct FDD type
Format Diskette or
No
Change Diskette
Check U605 (9956)
Pin1=5V, CN29 Pin53
No
(motor-ON0#)=5V
Check CN17 Pin51
No
(Motor-0N04) signal
Check CN17 Pin44
No (TRK0), Pin50 (step #),
PIN 60 (Index#) Signals
Check CN17
No PIN48(Write-Data#),
PIN46(Write-Gate#),
PIN40(F-Read-Data#)
Troubleshooting Procedures 5-21