Zenith Data Systems Z-171 PC Series Service Manual page 80

Page 6-6
System Checkout and Troubleshooting
STEP PROCEDURE YES NO
1d Disconnect the AC adapter from the com-
puter. Use a DVM or a VOM to check
the output voltage of the AC adapter. Does
the output voltage equal approximately 15
VDC? th le
le Unplug the unit and remove the cover.
Is the fuse blown? lf lg
lf Replace the fuse and return to step 1.
— —
lg Is the voltage selector jumper properly
set? li lh
ih
Select the proper setting and return to
step 1. — —
li Replace the AC adapter and return to step
1. — —
lj
Check the ELON signal from the main
logic board. Use a DVM or VOM to mea-
sure the voltage at pin 15 of connector
to step 1. = aaa
ll
Check the power output from the DC
power board to the LCD by using an oscil-
loscope. Measure the waveform at the two
leads of capacitor Cl as illustrated in Fig-
ure 6-2. Does the waveform approximate