Had a Hummy HDR some time ago that I "acuired" as non-working. Turned out to be acracked track under the PSU board (If I recall correctly, around the inductors close to the output conections). A few minttes with some tinned stranded wire and careful bridging all the dodgy track and it was running again.
You could check the PSU capacutirs - some fail.
See also some dedicated Hummy forums
http://hummy.tv/forum/threads/dead-box-can-any-one-help.2385/
https://www.avforums.com/threads/humax-hd-fox-t2-hd-receiver-master-thread-part-three.1487039/page-9
Loads more out there.
XXX
January 2016