Hi!
We had the same problem and it wasted hours of analyzing.
Hop, that the infos fit to your environment:
We discovered, that the APEX-switchbox is not able to transport the complete monitor-info to the pSeries.
If you install a blank machine with original AIX-CDs,
the installationroutine cannot identifiy which resolution can be used.
Our TFT is only capable 1024x768.
AIX-CD uses by default 1280x1024.
So you are able to install the machine while you are in text-mode.
When CDE is started, it uses 1280x1024 and the TFT stays dark!
When you connect a normal monitor (capable of 1280x1024) you will se the CDE-loginscreen.
This behavior can be reproduced by setting up from CDs or from am mksysb-tape.
Our official circumvention: When setting up a machine from CD or mksysb-tape, we directly connect the TFT to the VGA-connector on the machine.
In this case, the correct resolution 1024x768 is recognized and used.
When the system is runing fine, you can connect the TFT over the APEX-switch again.
If you already installed the machine, connect a normal monitor, change the AIX-resolution with smit, then connect the TFT again.
Hope this helps
Rudi