ES-4 turns on but SPDIF not lighting up and no outputs working

[jimsession]

Hi guys,

i considered myself lucky when i got a basically unused brand new looking ES-4, even in the classic orange color.
When i power it up i see all the LEDs flash for a brief second but the SPDIF light is not lighting up when i connect the coaxial cable from my interface.
I have a MOTU 828 from 2001, and i tested the S/PDIF output and it is working.
The ES-4 gets kinda hot on a particular spot but not too hot, you can still touch it - so i guess electricity is flowing through it.

Am i doing something fundamentally wrong or might my unit just be broken?

Would greatly appreciate any help as this is driving me nuts.
Thank you in advance!

[os]

Replied on ModWiggler.