Zenith Data Systems Z-171 PC Series Service Manual page 85

Page 6-1]
System Checkout and Troubleshooting
Step 5: RGB Video Board
STEP PROCEDURE YES NO
5 Connect a known good monitor to the
computer. Is anything (including an un-
readable display) shown on the screen? 6 oa
5a Are all of the video cables installed prop-
erly? Is the monitor connected to power
and switched on and is the computer con-
nected to the AC adapter? 5c ob
5b Connect the cable, connect the AC adap-
ter, and/or switch on the monitor and
then return to step 5. — —
5c Is the black level (brightness control) on
the monitor turned down? od 5e€
5d Increase the brightness and return to step
5. — —
De Access the video board. Is the video board
seated properly? og of
5f Switch off the power, seat the board,
switch the power back on, and return to
step 5. — —
og Is the AC adapter connected properly to
the computer? oh Ib
5h Measure the voltage at connector P1, of
the video board, as illustrated in Figure
6-3. Does the voltage of the two outside
pins equal approximately 5 VDC? 3] 5i
ay Replace the DC power board and return
to step 5. —_ —