The IEC socket is the power socket at the rear, and the module contains capacitors inside the housing. Changing this can fix the VOICE PROCESSOR MALFUNCTION cold boot problem.. Well, it did for me anyway!
No idea where i read to do this, but it's a weak point allegedly. It's not hard to change, and not expensive.
If You are having system stability issues, especially when you first boot, put this on the list of things to do.
I'll echo other comments in this thread - certain types of caps in [music gear] do fail usually - like those annoying tants, and the dreaded RIFA caps - those you can take a blind stab at no matter what You are working on. But unless You are *reallllllly* sure you need to, i'd avoid doing a blanket recap on anything.
If You have reason to service a board or a section, start with the larger caps, and test them as you remove them. If they are within tolerance after 2 or 3, then maybe it's not worth it.
I'm knee-deep in capping a 1986 Revox PR99 at the moment, and i'm testing as i go. It's actually shocking how out some of the larger ones are - 220's testing as 300+ uf etc. I'm replacing all the polarised tants with same value/voltage electros as a rule though, all tants must die. that is all.
Tim, EI4GNB