Quoted from brobra:I have a spare TZ clock board. I’m going to try to fix it today and address the post wires Ralph mentioned. My current TZ clock works perfectly at boot but after about 10 minutes it starts to error out. The 30 min opto reads closed. I’m wondering if the heat generated causes the flakiness to manifest itself. Any thoughts from my expert tech friends?
There are many threads on Pinside about clock repair. They are what I used when my gave me issues.