Ok, I couldn’t take it any longer without making a couple of comments.
You can break out the test gear and spend most of the day looking for the bad part or just replace the caps and transistor.
To start if you apply 12 vdc to the assembled clock and the balance wheel moves the coil is good. The wheel may move ever so slightly so look closely. If it doesn’t then the coil is bad and you need to find another board.
De-soldering /soldering is the biggest problem because you can cook the insulation on the coil wire. Once that happens you destroy the coil. No joke you need to be uber careful soldering the 10uF cap next to the coil. Guess which cap usually goes bad? These are electrolytic caps and you need to replace all with the exact values. No subs.
You can also have a bad transistor (C828) so why not replace it. Almost any general NPN low noise amplifier transistor will work. The zener diode rarely goes bad unless you’ve applied something like 24vdc to the board. I’ve seen it happen.
These 4 parts cost around $5 and will last years longer that the originals.
Last, but not least I don’t charge $351 to repair this board, that’s a completely refurbished clock converted to a Quartz unit. I do have this repaired 280z circuit board for $60.
Good luck and let me know if you need help.
Ron