Motor control board repair

[R_J]

Originally Posted by cyclones

It looks like the -15V goes back to SR3 and the voltage regulator that doesn't get warm, AVR2. From looking at the trace lines and from the meter, it seems like the AVR2 is in parallel. SR3 has a + and - and two middle pins that go to the AC input, so it seems like a rectifier bridge, but I don't know what the SR3 designation could mean. Any ideas?

Are you getting a/c voltage to SR3? It is likely a bridge rectifier, why it is labeled SR3, who knows.
If you are not getting any a/c to the bridge, check the resistance of the traces and the power supply winding that supplies that circuit.
What is the part number on SR3?