Yes, that is what you are looking for. Several manufacturers don't use a control board and the connections are made to colored pigtails with wire nuts.
What you are looking for is the Thermostat cable (usually colored brown) with eight colored wires in it. Once you find it, trace the blue and white wires and see where they connect. If they connect to the exact same point, then that is being run in parallel. Normally you want the white wire connected to the W2/AUX/E terminal so try disconnecting the wires at the end of the thermostat and using a multimeter measure between the white and blue wire (connect white to - and blue to +) if it shows short them both wires are good, if it shows open then there is a good chance the white wire is bad.
If that test shows a short between the two wires, then you can disconnect the blue wire on each end and use it to create a C wire.
Let me know what you find.
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