iMac won't turn on

I've read similar questions but my details are slightly different. My iMac is connected to a APC battery backup surge protector. The APC was going in and out of battery mode and while on Steam the iMac shut down. I've had issues in the past when the power goes out the iMac won't start. I usually get it back up and running by resetting the SMC and uninstalling and reinstalling the memory. I get nothing when I push the power button. No lights to indicate a fix to the problem. I've tried a second power cable and it's the same result. I removed the power supply and used a hot air gun on it per the suggestion of another post and it does not start. Where should I go from here?