[old_coot88]

There was a chronic problem with hybrid Sylvania chassis that looked very much like this one.
The collector load resistors for the two demod transistors were 2 watt carbon composition. IIRC, they were 27K (possibly 22K). They ran very hot, and over time their phenolic casing would char and carbonize, creating a low resistance shunt that dropped the ohms value drastically. This applied higher and higher voltage to the transistor (supply was something like 150V) until one of the transistors shorted out from overcurrent.

The sets would come in with a complaint of "bad color" from one of the demods being dead. The other demod was still working but severely overheating.
We would replace both transistors, and replace each collector load resistor with two 2-watters in series, giving each string a 4 watt rating. The values chosen were something like 12K and 15K.