Cleaning gas orifices
The simmer on one of my DCS dual stacked burners stopped working. As in the past, I took off the simmer ring and cleaned the holes with a paper clip. Didn't help. I swapped rings with another burner and discovered the problem wasn't with the ring itself but with the burner. Gas wasn't getting to the burner for the simmer. I remembered an old post by arthur_ogus and as arthur pointed out, there is a second gas orifice in a small hole beneath the simmer ring. You can't really see into it even with a flashlight. Tried using a paper clip but it was too thick to go beyond the bottom of the hole into the orifice. I found a set of tools on amazon (different size wires) for cleaning gas orifices but didn't need to order them. I found a video on youtube (by GE) about cleaning gas orifices. They suggest taking a twist tie that you use for sealing bags of bread or garbage bags and stripping off some of the plastic to expose the wire underneath. I did this and was able to insert it into the gas orifice - had to do it by feel since I couldn't see into the hole and sure enough this worked!
I'm really proud of myself! I hope this helps some other DCS owners although arthur's old post implies that newer DCS models don't have two orifices per burner. I don't know if this actually impacts the simmer or just simplifies things. Actually this can help any gas range owner whose gas orifice gets clogged. Here's a link to the video.
Here is a link that might be useful: Cleaning a gas orifice.