Clean the contact in the PLAY button.
Check for cracked solder joints at the board. Particularly where connectors are soldered in.

And keep in mind, that the deck won't start without a record on the platter!

Martin

Martin,

Thank you and yes, I always put a weight on the center disc, an easy mistake to make if you've not already made it (which I did when I worked on my first B&O table)

Martin,

Start button cleaned, resistance v low when operated, measured at the connector, so wiring good. Still nil response.

WIth deck vertical, no platter or cartridge, I turned the large gear slightly clockwise. Platter started turning and arm operated (cue down, move to edge of record. 

Buttons still inoperative.

Simulating end of record caused the large gear to turn as expected, return arm to rest and stop platter. 

During this, two LEDs by the speed buttons and one by the start button were illuminated.

This link shows the gears in play and stop positions.

https://photos.app.goo.gl/GdqbuxvfotF9qAkz5

Next steps please?

I'll admit that auto record player mechanisms, with the exception of B&O parallel trackers, are my weak spot

Am I getting a broad hint that these aren't economic repairs except for really simple stuff? 

That's where I'm heading

Did you reflow the solder joints, I suggested?

Martin

Yes, all the joints on the control panel board and all the connectors, including the power transistor socket, on the main board.