Blank Screen - No Output

Problem: Your system screen is blank and does not show any output.

Here are possible causes for this problem:

• Hardware has failed.

Refer to your system documentation.

• Keyboard is not attached.

If the keyboard is not plugged in, the output goes to TTYA instead. To fix this problem, power the system down, plug the keyboard in, and power on again.

• Monitor is not turned on or plugged in.

Check the power cable on the monitor. Make sure the monitor cable is plugged into the system frame buffer; then turn the monitor on.

• output-device is set to TTYA or TTYB.

This means the NVRAM parameter output-device is set to ttya or ttyb instead of being set to screen. You can do one of the following:

• Power the system down. Then turn it on, and immediately press Stop-N. This sets all NVRAM parameters to their default values. As a result, the output-device parameter is set to screen. Be warned that all previous non-default settings are reset to their default values as well. You must restore them as needed.

• Connect a terminal to TTYA and reset the system. After getting to the ok prompt on the terminal, type: screen output to send output to the frame buffer. Use setenv to change the default display device, if needed.

• System has multiple frame buffers.

If your system has several plugged-in frame buffers, or it has one built-in frame buffer and one or more plugged in, then it is possible that the wrong frame buffer is being used as the console device. See "Setting the Console to a Specific Monitor".