When plugged in, I can hear a faint ticking sound...

OK, I opened the unit and can see and smell a burn mark on the circuit board near C423 and resistors R423 and R424 (which do not look damaged at all). The burn area on the circuit board extends in the general area of these three components. The components themselves do not look damaged at all, just burn marks around the circuit board in that general area. I measured the resistance of the 2 resistors and they are both measuring the correct resistance (supposed to be 100 Ohms, they are measuring 96 Ohms and 90 Ohms)

I am not sure how to check a capacitor.