[james1095]

I use an ordinary 100W incandescent lightbulb in series with a set the first time I power it up. If the bulb glows brightly and stays bright, something is wrong. If it starts out bright and then dims down, things are looking good.

When it comes to testing components in circuit, you really need to have the schematic in front of you to see if any other parts are wired in parallel that could throw off your measurement. A resistor checked in circuit should never read higher than the rated value, but it may read lower if it has something in parallel.

As for transformers, my experience has been that they almost never fail on their own. It's almost always a short somewhere else that burns them out. There is some good general information about transformers and winding here:

http://ludens.cl/Electron/trafos/trafos.html