RCA Radio Model 641 - First Look 

Everyone has a different approach to this. I like to change the smoothing capacitors, and the capacitor feeding the grid of the output tube (since, if it's leaky it will bias the output tube on hard, thus possibly damaging the output tube, or the output transformer). So I do those caps before trying the set.

Those giant resistors are actually plastic encased wax paper capacitors. They are all leaky by now and must be replaced. This is a transformer set so it will be easy to switch out the hot side to the on/off switch ( use a new polarized power cord). Pull the rectifier tube out and power on the transformer and check for voltages. Still learning , but a flowchart of how to go about things is a good method to do so as to not make too many errors or waste time on it. For instance if the power transformer is bad don't waste time on doing more work on it. You will need a new one. Just saying experience is the best teacher.

Replace all the the black beauty or bumble bee caps as they are so leaky by now or they have changed value.

Have you ever worked on a radio before? It’s not showing. 😊