Newbie with a Techics problem

Old Nick2

Hi all just found this interesting forum and hope someone can help with a Technics problem.
I have just purchased a Technic SH-GE70 equaliser which I have connected to a Technics A900S Amp and a Technics SU800UM2 Pre Amp.
To do this I have the line output from the equaliser to the power amp and line input on the equaliser to the Pre Output socket on the pre amp.
This setup works but the display on the equaliser does not fully function as it only shows a static small bar display and if I try an connect anything to the tape input output sockets the whole thing goes into overload!
I have connected a CD player direct to the equaliser (without any other connections) and the display works perfectly.
I guess there must be a simple answer but I'm blowed if I know what it is!
Any help from you experts would be much appreciated.