Troubleshooting Procedure For No Video Display - Digital Equipment VAXstation 3100 Maintenance Manual

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Troubleshooting 21
2.2.1 Troubleshooting Procedure for No Video Display
Each step in this troubleshooting _ p rocedure instructs you to disconnect a
FRU,
power-up the system, and detennine if the problem still exists. Each
step describes a different
FRU
to disconnect. You must disconnect an
FRU
as described in each step until the system powers-up normally. Once the
system powers-up normally, the last
FRU
you disconnected is the failing FRU.
Replace the failing
FRU
and retest the system for any further problems.
1. Check the video cable for a good connection on the monitor and on the
system box. Make sure the monitor is switched on. The LED on the
monitor should be lit when power is supplied. Turn up the brightness
control until raster is observed. If no raster appears on the screen, refer
to the monitors pocket service guide to check the video monitor.
2. Power down the system. Check the position of
ls3I
on the back of the
system box. It should be in the down position if the monitor is used as
the console device. It should be in the up position if a terminal is used as
the console device (the tenninal should be connected to the printer port).
3. Remove the system box cover, disconnect the MSC cable betwen the
system module to the MSC module, and disconnect the power cables to
the drives. This disconnects the MSC module and all of the drives from
the system.
4. Power up the system with the MSC module and all drives disconnected. If
the system still has no video display, the problem is not with the drives or
the MSC module, proceed to step 4. If the system has a video display after
disconnecting the MSC module and the drives, power down the system,
reconnect the MSC module and then power up the system again.
If
the
system bas no video display again, replace the MSC module and retest the
system. If the system has no video display after reconnecting the MSC
module, plug in the drives one at a time until the system fails. Replace
the drive that prevented no video display.
5. Power down the system, remove drive mounting panel(s) from the system,
and remove the graphics module from the system module. If the graphics
module was not installed, proceed to step 6. When you power up the
syst· e m after removing the graphics module, you must either connect an
alternate console terminal to the printer port and set the ~ to the up
position (9600 baud rate) or watch the LEDs to see if the system has
a video display or not. The alternate console is used because when the
graphics module is disconnected, the monitor is disabled.
6. Power up the system with the graphics module disconnected. If the system
has no video display, the problem is not in the graphics module, power
down the system and proceed to step 6. If the system has a video display,
replace the graphics module and retest the system.