As soon as I have been able to replace the inductor, I will let you know the result.
Did you see the atachments in the opening post? At first glance L1 looks normal.
It would have been easier for me to troubleshoot if the L1 had also been burned.
Received 2 replacement inductors by mail this morning.
Ian, thank you for that.
L1 has now been replaced and the HV can be set again to 175 volts!
It turns out that only two parts have broken, namely L1 and the MosFet. The MC34063A had remained intact.
I took a few pictures of the good and broken inductor in my transistor tester and of the working clock.
I thank you Ty and Ian for your help and your time and it was nice that I was not alone with the problem.
I'm going to enjoy the clock again.
Best regards, Wim.
Last edit: 2 months 2 weeks ago by Ian. Reason: Put pictures inline