What could cause resistor to test as shorted?(two of the same chassis)

[AE35]

Hi !

I have two of the same chassis, one works and the other works, but one of the vertical transistors gets very hot.

On these chassis there's a large 160ohm 20W resistors in the PS section, and on the good chassis this
tests fine in circuit, but on the bad chassis it tests as shorted. When I lift a leg, it tests as it should.

So, are there any components that *generally* cause a resistor to test as a short?

It's the big resistor in the top:



Thanks:)

[BobA]

If the resistor checks OK with a leg lifted then it is a component in parallel with the resistor that is shorted.  Look at the circuit diagram or post it here.