This is a common problem in servicing. As an EE, I want to know
exactly why something isn't working correctly. But I learned a long
time ago that it's more important to simply get the damned thing
fixed. If that means shotgunning likely components, so be it.

Shotgunning is, IMHO, very bad practice, and often leads to the
creation of more problems than it fixes. I am actually quite surprised
that you would advocate doing this, William.

I don't understand how shotgunning can /create/ problems, as long as the
replaced components are correct replacements. Unless you mean the customer
might get upset.

As an experienced service technician, you know that the cause of a given
problem is not always obvious, even after extensive troubleshooting. The
customer is paying for your time, often more than what the parts cost. Why
burn up the customer's money when replacing a half-dozen parts is likely to
fix the thing?