How to connect HDMI monitor to my AutoPi TMU

I need to connect my HDMI monitor to the autopi TMU unit. I want to use the monitor as a dashboard display showing the autopi dashboard.
I tried to setup iceweasel with xorg/xinit and xserver setup to login as user screen but nothing gets displayed on the HDMI after boot up. It appears the HDMI is shut down. And I can’t connect through ssh to the TMU.

help needed urgently