Air Conditioning - Goodman air handler fan not running

My Goodman A32-10 air handler fan will not start when the t-stat is switched to "on" or "auto". The outside unit will start OK and the air handler will emit an audible electrical hum or buzz but the fan will not start.

I've checked to confirm power to all the major components including the fan motor and everything seems OK (using a voltage tester, not a meter). I'm guessing the culprit might be the transformer but I'm not sure how to test. Any ideas or suggestions as to the potential source of the problem and ways to diagnose? :confused:

Of course this happens when the night temps are falling to an unseasonably low high 20s in Austin, TX. Arrrgh. This is the third time this unit has stooped working this year. So far I've been able to trace the problems to relatively easy fixes and I hope this will be the same situation. Thanks in advance for your replies. This site is amazing!

Does the fan start running if you give it a little spin in the same direction that it runs in?

No the fan will not start with assistance. The fan spins OK so I guess the bearings are OK but not sure about the motor. Motor is receiving power (confirmed with voltage sensor only at this point).

I would recommend replacing the motor and capacitor.

Correction...I had not given the squirrel cage a manual spin when the t-stat fan was set to "on". I tried this and the fan motor started up. Would this mean the run capacitor is bad? Is there a way to test the capacitor or should I just replace it?

just replace the capacitor they are dirt cheap.