TheWumpus:
cr0sh:
If you can in some manner, check the voltages without the outputs of the IC connected to the base resistors; likely the rest of the circuit is "getting in the way".Any idea how I can do this?
Well - you need to locate the base resistor, assuming one exists. Trace from the output pin on the RX2 IC to the transistor it drives - hopefully somewhere there is a base resistor. Then you need to open the circuit at this point - by cutting a trace, or some other method. Then measure the output of the pin to ground. You may want to try first (just in case I'm wrong) to open the circuit -after- the base resistor, and measure the voltage from that point to ground. In case going directly to ground (even with a meter in between) draws too much current (and poof goes the output stage of the IC).