Aging Solid State Electronics - R&R question

[DataCruncher]

My board is out of warranty/legacy, so have to either rely on sparse 3rd party vendors or DIY.

[DANSPEED]

Anyone know of a reliable source for quality components in Canada?

Digikey
Newark

Digikey is in Thief River Falls, MN but shipping to Canada is fast. I've bought parts from both for years.

Is there a way to test components still attached on-board, or must certain types be removed in order to attain accurate readings?
And when searching for weak-links, which parts would be first to consider.
Capacitors?

You can test in-circuit but without schematics the readings won't mean much unless your looking for basic shorts or opens. Even a short won't mean much if your testing around a switching power supply. If the board your troubleshooting has four or more layers don't try removing parts with a standard soldering iron or gun, especially through-hole rail capacitors because the large copper planes will rob the heat required to melt the solder. You really need to use a hot air rework station or a desoldering station. A solder sucker won't do it. At that point it might be cheaper to source a new or used board. A weak link component depends on what your troubleshooting. Capacitors are a good start because they can degrade over time or in the case of tantalums short for no good reason. I worked on a 14" CRT monitor years ago that would overcharge the tube to well over 50KV and send out a discharge spark three feet away! Turned out to be a bad 10uf/25V cap in the over voltage detection circuit. I've seen bad ceramic caps in timing circuits and shorted caps in reset circuits. But the AC capacitor in my 67 year old DeWalt radial arm saw still reads good!

[DataCruncher]

Thanks for that info, DAN.