Yes, On the very early production versions of the BG4002 and BG 6000, they probably still had a large stock of vaccuum sockets available from the vaccuum days, so that's what they used to connect the CD4-RIAA PCB. More proof that the old over-engineered stuff is so much better. In the later production versions, they used a flat socket, so flimsy

Paul, You're on the right track - but on the actual signal path itself, remember that the coupling caps are there primarily to block DC (the best capacitor is no capacitor at all), so the objective is have a capacitor which affect the signal audio as neutrally as possible. Today, with the advanced technology of film caps (Wima MKS2), you can quite

Good job Paul! My "invention" is certainly not a patent, and I'm very pleased to see others using it! Actually, B&O started using LEDs for these sensors in later production versions. But that took a redesigned PCB to do the job. Here you can see the 1K Resistor mounted Menahem

And #3 is the mechanical check - remove the squarish cover at the rear of the tone arm, and look from the rear, at the tonearm assembly. Lift up "c", and check that the tonearm is able to move up and down freely. You will need to balance the system afterwards anyway - also in the SM. Menahem

OK, # 2 is the pivot control setup - the alignment of this is critical - if it is not aligned precisely (all other factors being OK), the arm will not drop. I always convert these to LED's, and here you can see the yellow LED. Alignment is in the Service Manual.

Sam, I'm puttimg up a couple of pictures - check to see that your's looks like this. Beyond these 3 areas, you may have afaulty control PCB, nad only a proper restoration will ensure flawless operation. This one is the LED which illuminates the slide ruler - it should not be in a plastic enclosure. Opposite it is the photo-transistor sensor

You may have the sticky piston problem - I've seen that a few times in these caused sudden shutoffs. The piston needs to be rebuilt. This is a problem common to the whole range of the Type 59xx turntables. Menahem

I haven't seen this particular solution to this problem before, but I'll certainly be filing it on my repair card, if I see one of these again - thanks Martin! Menahem

Right Peter, That's why I like the BM3400 - it came in 1976 just before the 4400, when B&O was still on the up-and-up, approaching the peak of quality, before the bean-counters stepped in. Menahem

Anything, except rewind the armature - if that's shot, then I can't help you. You can test the armature windings by connecting a "ring-tester". Menahem