Texas Instruments 660 - Manual (Page 84)

5-24 Troubleshooting Procedures
Figure 5-8 CD-ROM Interface Troubleshooting Diagram
7
Checked CD-ROM Power?
Check U605(9956) Pin1
VCC-CDROM=5V
Checked CD-ROM Data
Bus?
Check U13
PIN 36, 37, 38, 39, 50,
51, 52, 53, 62, 63, 64,
65, 71, 72, 73, & 74
Checked CD-ROM
Address Bus?
Check U13
PIN68, PIN69, PIN70,
HSA0, HSA1, HSA2
Checked IRQ Signal?
Check U13 Pin86,
DIRQ15
END
Yes
No
Yes
Yes
Yes
No
No
No
System Fails to Boot:
CD-ROM Interface Checks