Just adding another update/confirmation to the discussion, nothing new here. This is my third replacement of caps in six years.
About four years ago (2016 ish), on v1.x PM, I replaced all 5 caps per original post, and confirm it fixed my issue to replace those five caps with the higher values shown on first page of this discussion. Repeat about two years ago (2018 ish), replaced only C7 and C13 using 10uF 50v caps and it solved that unit.
This week (Sept 2020), my un-modified v2.1 PLM bit the dust after a brief power outage. Still had green light, but my ISY unit would not communicate with any of my light switches/dimmers.
I removed and tested the C7 and C13 caps from my v2.1 PLM. They were 47uF 50v "Topmay" brand. One tested at 46uF with 1.2% loss and ESR of 1.2ohms. The other tested at 41uF, 12% loss and ESR of 140ohms. I replaced both with fresh 47uF 50v "Topmay" (I just happened to have same ones in stock), and it fixed the issue, ISY re-queried and all is working normally.
More recent posts tend to confirm anything from 10uF to 100uF 50v for C7 and C13 will work. Presumably 100uF may work better (?). Bottom line is, replacing C7 and C13 is definitely a good first-step to see if that resolves a broken PLM module.
