I'm also surprised that B&O fitted these caps in this loudspeaker... usually they should fail after some time. Use the same capacity, 15 or 16uF doesn't make a difference, but use 100V types. I would prefer 100V, it's more reliable. If a 40/63V cap fails, it can cause severe damage to a speaker...

Yes, quite normal bipolar electrolyt caps were probably used. And they would work fine... and they are very cheap. I think, 2-3 Euro in total. But if you want to improve the sound, use plastic ones. Electrolyt types have some acoustic problems, they cause audible distortions.

In this plan are bipolar caps used, no polarized. So, somebody has replaced your caps with the wrong ones. They are definitely wrong. In this application plastic capacitors (type WIMA MKP or MKT ) should make the best sound, dont use standard electrolytic bipolar caps.

Neither nor... first check the circuit plan. The best sound are (bipolar) polyethylen or polycarbonate plastic capacitors. But it is more important, not simply to replace parts, but to understand why B&O and the designer used this parts. Maybe it's pssible, to reduce parts or even to improve the design.

OK, you are right, these are really polarized caps, 100%. A bipolar cap consists internally of two polarized caps with common ground. Maybe this fact was used to design this crossover network. 2 polarized caps are cheaper than 1 bipolar. The circuit plan would be very interesting ;) Sorry, i dont have this plan, to old...could somebody post it?

Are you really sure, that the crossover has polarized capacitors? Really really sure? 100% ? Usually they are all bipolar. If you use polarized capacitors and there should be bipolar, then you wont have fun with these parts. More or less they will get destroyed with all consequences... The auricaps should work, they are an equivalent for the Wima.

Yes. It is also possible to remove the 2 defect power transistors. Then you can check the other channel. If the other channel is ok and music plays, then you know that power supply, tuner, controls are 50% ok. The BDV64 / 65 are very old and rare, but good Hifi parts. Do not use other types for replacement! But if it is possible to adjust the no load

Maybe somebody has switched on the S_VHS Input. Try SHIFT-9 It's a toggle funktion.

Ok, you are on the right way... 78mV is too much, the power transistors BDV64/65 become too hot even in standby. I would replace both potis... no problem, the bottom plate can be removed easily, there is no need to disassemble the boards. The next problem is, that the power transistors TR1xx probably are already damaged, they should also be replaced

No problem... . That's why we are here.