Tony Hwang wrote, on Tue, 23 Dec 2014 13:57:56 -0700:

I know same is the case with HSI(hot surface ignitor) Never touch HSI
with bare hand, finger oil will shorten it's life, also it is quite
brittle. And cover plate removed, don't forget to cheat the interlock
switch.

I taped over the door switch, so that's not a problem.

Thanks for the warning on the brittle igniter.

Here, where I've removed the three burner tubes, you can see that
the speckly igniter is only at the top burner, while the rod-shaped
flame sensor is only on the bottom burner, with the middle burner
being left alone:
https://c4.staticflickr.com/8/7467/1...609d3825_c.jpg