Zenith Z-171 Series Service Manual page 83

Page
6-9
System Checkout and Troubleshooting
3b Check the disk drive power cables. Are
they installed properly?
3d 3c
3c Install the cables and return to step 3.
3d
Is the drive configured properly?
3f
3e
3e Refer to "Configuration", Chapter 5 for the
proper settings. Return to step 3.
3f
Change the Setup menu to set the com-
puter to autoboot Check the control sig-
nals from the main logic board by per-
forming the following procedure. Remove
the J5 connector. Prompt the computer
to boot drive A by turning the unit OFF
and then ON. While the computer is
try-
ing to boot drive
A,
use a DVM or YOM,
to measure the voltages at the following
pins of connector J5.
Pin l'
+
5VDC
Pin 3
+
5VDC
Are these voltages correct? 3g
3h
3g Boot a MS-DOS disk in drive A. To
prompt the computer to select drive 8,
press the RETURN key after the date and
time prompts. Enter B: and press RE-
TURN. enter DIR and press RETURN.
While the computer is trying to read disk
8, use a DVM or VOM to measure the
voltages at the following pins of connector
J5.
Pin 5 + 5VDC
Pin 7 + 5VDC
Are these voltages correct? 3i
3h