So, in conclusion, I would definitely say that in my daily repair
experience, electrolytics are now by far and away, the commonest
component to fail, and this, IMHO, is for all of the reasons that I have
stated.

Arfa

agree, but it may be worse than just replacing the caps.
Most switchers start with a higher voltage.
As the capacitance reduces and the series resistance increases,
the regulator maintains an average output voltage somewhere near
the spec. Problem is that the load electronics cares about the peak
voltage too. High voltage spikes can take
out all the downstream electronics.

Maybe it doesn't matter when labor costs exceed the cost of a new device,
but I think the fun times are coming to an end for those of us who
like to buy cheap busted stuff and fix it.

Anybody want to buy a monitor with a logic board killed by 20V overvoltage
spikes?


Depends, I think, on the design of the PSU, and how it regulates. I have
seen cheapo items where a failed secondary side cap has allowed the 5v rail
to virtually double, resulting, as you say, in trashed LSIs downstream.
OTOH, I have seen secondary side caps that are in such bad physical
condition, being domed, and with the plastic melting back, that no
diagnostic tool other than the mk 1 eyeball, was needed to spot them, and
when they have been replaced, the item has come back to full and normal
working order.

Arfa