Texas Instruments 660 - Manual (Page 81)

Troubleshooting Procedures 5-21
Figure 5-5 FDD Interface Troubleshooting Diagram
4
BIOS Menu
Setup
Enter Correct FDD type
Floppy Diskette
properly formatted?
Format Diskette or
Change Diskette
FDD Power Checked?
Check U605 (9956)
Pin1=5V, CN29 Pin53
(motor-ON0#)=5V
FDD Motor Checked?
Check CN17 Pin51
(Motor-0N04) signal
END
Yes
No
Yes
Yes
No
No
No
Seek Operation Checked?
Check Read or Write
Operation
Check CN17 Pin44
(TRK0), Pin50 (step #),
PIN 60 (Index#) Signals
Check CN17
PIN48(Write-Data#),
PIN46(Write-Gate#),
PIN40(F-Read-Data#)
Yes
Yes
Yes
No
No
O.K.?
System Fails to Boot:
FDD Interface Check