Resistor Behavior Question

[vts1134]

I've witnessed some behavior on a resistor in a set that I'm working on and would like to know if it's normal. I have a TV chassis that I have replaced all of the electrolytic capacitors. I will be replacing the paper caps as well, but I wanted to get a baseline for how much the set is functioning before I move on. Bringing up the voltage slowly on the set to around 2/3 line voltage I noticed that one of my resistors started to "boil." That is to say the area around one of the leads began to bubble up a bit and out-gas a very small amount of smoke/steam. I only had voltage to the set for a few more seconds once the resistor started to do this so I'm not sure if it was a temporary thing or if it would have eventually burned up. I just wanted to know if this is ever normal for an old resistor to behave like this when it's being powered up for the first time in possibly decades, or if behavior such as this is always indicative of a greater problem in the set.