In circuit resistor testing?

[kbmuri]

The best way to check resistors in-circuit is to take all the tubes out of the set, get a Sams sheet for the set, and do the entire resistance chart from top to bottom. If every check in the chart checks out, you've probably checked all of your resistors. If a chart entry does not check out, trace the schematic's resistors between point A and point B (of the current chart check) and make sure your set has the same ones. Sometimes the chart is wrong, when the unit they took original readings from is a slight production-run revision from your set (I learned the hard way). If the resistors in your set are different, but the resistors in your set between point A and point B add up to what you're reading, in the same way that the resistors in the schematic add up to what's in the chart, then you're still ok. If you get a reading that can't be explained, then lift the leads of the resistors in that path. If they check out, then probably you have a short or shorted capacitor nearby. If they don't check out, then of course replace them. You can pass 95% of your resistors this way, leaving them in-circuit.

Also if you have the Sams sheet, then you don't have to guess if 1/4-watt is ok or not. The parts list will tell you what wattage you need. Doesn't hurt to go one step higher (e.g. a 1/2 watt where 1/4 is called for), in case your 50-year-old TV isn't as up-to-spec as it was when it was born. But that's just me being cautious. I imagine the parts list knows best and you're fine meeting what's called for. Never go under, of course.