NEC MH4500 - Manual (Page 111)

Solving Problems 5-9
3. Run the SSU to disable the onboard video controller.
4. Reboot the system for changes to take effect.
If there are still no characters on the screen after you reboot the system, contact
your service representative for assistance.
POST emits one long beep and two short beeps pattern to indicate a possible
problem with the video display controller. If you do not receive a beep pattern
and characters do not display, the video display or video controller may have
failed. Contact your service representative for assistance.
Characters are Distorted or Incorrect
Check the following.
T Are the brightness and contrast controls properly adjusted on the
monitor? Refer to the documentation supplied with your monitor.
T Are the video monitor signal and power cables properly installed?
T Is the correct video monitor board installed for your operating system.
If the problem persists, the video monitor may be faulty or it may be the
incorrect type. Contact your service representative for assistance.
System Cooling Fan(s) Does Not Rotate
The system has eight cooling fans. In addition, each power supply has its own
cooling fan. If any of the fans are not operating properly, system components
may be damaged. Check the fans periodically, as follows.
Note: If a power supply fan fails, call your service
representative. There are no serviceable components inside
the power supply. If the power supply is opened, the
manufacturer's warranty is voided.
Check the following.
T Is AC power available at the AC wall outlets?
T Are the system power cords properly connected to the system and to the
AC wall outlets?
T Did you press the power on/off switch on the front panel?
T Is the fan failure indicator on the front panel lit? If so, a fan has failed and
must be replaced.
T Is the power supply failure indicator on the front panel lit? If so, check
the power supply failure indicator on the power supply to determine
which supply failed.
T Are the power indicators on the power supplies on?