Thank you for your replies. I know how to load early deployment firmware.
Currently I run the General Availability version 6.4.4.8-4.2.4.6. It explicitly says that the code is also for the 205H:
When I look at the Early Deployment version 6.5.1.0-4.3.1.2, the 205H is not mentioned. I read that as this firmware is not suitable for the 205H.
Previously I loaded a firmware version which was marked for IAP204/205 on my 205H and it was bricked. I had to reload the previous firmware on the 205H via console.
Can anyone clear this up?