Installation guide

Troubleshooting
Getting Started with Troubleshooting
1-10
Symptom: If the Display is Dark
The control lines for the A4 Inverter are routed from the A12 CPU through the A23 Motherboard
and the A3 Front Panel Auxilary Board to the A4 CN1 connector. The +5.2 Vdc is routed from the A6 Power
Supply through the A23 Motherboard and the A3 Front Panel Auxilary Board to the CN1 connector
of the A4 Inverter.
Figure 1-3 A4 Inverter Connections
❏ Check that the screen saver is not on.
— Press any front panel key to disable the screen saver.
❏ Check that the signal generator is powered-on and the front-panel green LED is lit.
— If the green LED is not lit, refer to Troubleshooting Assembly Level Problems on page 1-23.
WARNING High voltage is present at the A4 Inverter output (CN2-1). Also, while measuring
CN2, be careful of the fan blades on B1, B2, and B3. Keep hands and fingers away
from the fan blades to avoid injury!
❏ Check the voltage, using a DVM, at the A4 Inverter output (CN2-1).
— To access this connector and measure the voltage:
1. Disconnect the front panel assembly from the chassis frame.
2. Slide the front panel display away from the chassis while ensuring that the ribbon cables to the
A23 Motherboard stay connected.