In case you have removed all the necessary screws (double check!), there's nothing holding the amp unit in except the remains of the gasket foam, which now resembles glue. You might need a scary amount of force, but eventually it will start to give. Pulling it by hand is usually hopeless, so you really need to pry with a tool. Don't scratch the tube, and be careful when the amp comes loose, as it is surprisingly heavy. The cables coming off it don't have much spare length either, you will need to detach some connectors before the amp comes safely away.

The damping material inside the speaker can also be quite disgusting after it has aged. The actual problem might indeed be a blown fuse or (IMHO more likely) a broken standby transformer.

Thank you so much Mika. Held my breath and push hard with a screwdriver and it opened!!

Unfortunately I thought they were ordinary fuses :(  This will be a bit more work to change!!

The mess from the foam is quite bad too!

Another question....what do you call those black fuses? Is there a special name for them? If it isn't the fuses...is the standby transform a common part to get or will I have to get from B&O?

Thanks

Ben

Another question....what do you call those black fuses? Is there a special name for them? If it isn't the fuses...is the standby transform a common part to get or will I have to get from B&O?

Thanks

Ben

Unfortunately I don't remember at all how those fuses looked like. If they are these:

...they are TR5 miniature fuses, and every decent component supplier should have them.

If you didn't even have the red standby LED, the transformer is a suspect. Just measure the windings for continuity and you'll know.

The transformer will be easiest to supply from B&O. I suppose it is a stock model from some manufacturer, but trying to find a pin and footprint compatible replacement - and somebody who agrees to sell 1 pcs of them - will be a lot of work!

BTW, the internal damping foam kit should be available as a spare part as well and not too expensive. May not be worth it though, if you don't plan ever digging in there again!

Do you happen to know what the output voltage is from Standby Transformer T2?

No... not specified in the service manual. The standby power supply creates +/- 15V so it wouldn't need to be much more than that, but one half from the transformer appears to be used to supply ~27VAC to operate the mains relay (24V coil).

Therefore, I suspect 2 x 24V, but I'm not going to open any of my working speakers to measure it 😁