I know this doesn't help much...
I made 3 of them. The 1st worked pretty good, and I hastily checked it; and I build a 2nd and sent it to a friend.... Arogantly, i didn't check it -- and it didn't work.
The one I had worked on all but one range; so unsoldered the parts that were relevant to that circuit. I tested each part & resoldered. Still no go. Since I had 3 boards, I just built the 3rd -- it totally didn't work... at all. Worse than the one i sent to my friend.
I tested each part, again, and all seemed ok.
I then measured the switches... I think that might be where the problem is, the resistance on the switches (the 4 that I had here) all measured different resistance.
Someone suggested that it might be A/C interference, so I put it in metal project box and it didn't help either.
My friend, who builds boards for a living, striped the board & rebuilt with new parts; still had issues.
I ordered some of the 'non critical' components (those that are not spec'd at 0.1 or better tolerance) with better tolerances to see if that helps, but the switch is still the weak point. I am just grateful that i have one (out of 3) that works on 2 ranges... but that's not good when you consider it's 2 out 9 ranges that worked....
I never got a reply to my post...
(I found your post because I needed the dead range to work & started searching for solutions...)
Sorry I have no helpful news, but I guess "you're not alone".
I used all the parts as specified...