I've noticed that recordings made almost 30 years ago appear to have self erased, none are as loud as they once were and high frequencies seem to have attenuated. For the most part, if I can reuse the old tapes this isn't an issue, except for one thing, the azimuth aligning tape appears to be completely blank, at least I'm not seeing anything on the VU meters or hearing enough to confidently adjust the azimuth and know I’m not doing more harm than good. Any ideas on how I might be able to recreate or replace this tape?

Additionally, I uploaded a video http://youtu.be/Kgq1hx2RYbw so you can see what prompted me to want to check the azimuth. If I record one side of a tape the playback sounds perfect, but when I record both sides of the same tape I get crosstalk. Could it be that every one of my old tapes are no good or might it be an issue with the Beocord’s circuitry?

FYI: The tape I used for the video is a TDK MA-R90, probably the best tape I have, but every tape I've tried so far is doing the same thing. Regardless, I would like to have a working azimuth aligning tape, preferably the original one that came with the deck.

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It turns out that the azimuth was way off. I was able to use a mono tape to bring the adjustment back. Thank you Dillen for giving me the idea. Once the azimuth is reasonably close the factory tape works fine. Now the question is, what would cause such a drastic change? Did something break or perhaps the last time service was performed the transport wasn't assembled correctly?

All tape and especially Type II (Chome) will lose a couple of dB in strength over the years as the oxides weaken over time

Also, rough transport and many plays can wegde azimuth out of adjustment.

If the azimuth seems to be WAAY out on one of these "wedge-shaped" cassette machines, it's usually caused by a crack(s) in the plastic molding(s) on the mechanism that holds the springs(s) that keep the head-block in place as it moves back and forth.  The little clip that holds the cassette in place when it plays sometimes keeps things working okay, but it's not consistent, especially among different tapes.

BC9000 is a wonderful deck when it works correctly; keep in mind that it may need a comprehensive service if this has never been done before.

My complete Beosystem 8000 is due for major service, I just been feeling like a kid on Christmas Day since I opened the boxes, which for the most part had been in storage since 1988. Of course I tell everyone that I need to discover exactly what the problems are so I can pass this vital information on to the service people.

When I made the initial azimuth adjustment, the mono tape and B&O's alignment tape didn't exactly agree so I settle on something pretty close to midway. This was close enough to get the deck working quite well, playback seemed fine and my test recording revealed no audible crosstalk. Since then I have relied exclusively on the B&O tape to tweak the azimuth adjustment twice, now the deck really sounds fantastic, but I have only been playing with one tape. I intend to keep checking the azimuth and normally I use a variety of tapes so if the plastic is broken I’ll definitely want to get it fixed.

How hard is it to get parts and do you have any idea as to cost?

Try adjusting the azimuth and then setting the screw with some nail varnish, just be careful that it only goes on the screw tho!

Regards spares for this deck your only hope for most of it would be to purchase a spare deck and butcher for parts. They are extremely cheap atm, and considering what other tape machines can fetch and this machines historical importance to the tape market (first deck to ever feature HXpro and surely amongst the first to feature Dolby C???) I think they are currently undervalued to some extent!