hifi engine

I need the service manual for Cyrus LFAU bass amplifier for mission 767 speakers

I recently acquired a pair of the mission 767 which come with the Cyrus LFAU dedicated bass amplifier, unfortunately the LFAU does not seem to be working as there is no bass output out of it. The light comes on but nothing else happens, I was hopping to see if you can give me the service manual for this unit ( hopefully in PDF format). I opened it up and seems that the 4 Amp fuse on the left is blown after changing it it did the same so I am assuming there is a short somewhere. Please help me as It took me a very long time to get my hands on these speakers and I can't wait to listen to them. and it is impossible to listen to the speakers without the LFAU apparently