I got the HK2500 tapedeck up and running. Just new belts then OK. Then I tried my testtape in it, and the tape was full of dropouts, and very bad overall.
Then tested a lot of my old tapes and most of them had dropouts.
(Old tapes loose their megnetism)
But found 2 good ones (99 % good) and gave them to B&O 8004.
Holy moses, it worked. ! Both channels, VU, dolby in/out, timerdisplay. All fine.
(until now, maybe some details isnt working, but so far so good)
So you were right Martin and I was getting "blind" and forgot the testtape, and only focused on the 8004.
Thanks for keeping your interest and continued help. Very grateful and happy.