No Power on DDJ SX2 after firmware update.

Have you tried to reinstall the firmware?  Also did you shut off the power during the install?

Does the SX2 illuminate the normal buttons when it's powered on ... and if you connect it by USB, does it then show any change?

I've run into this problem as well after updating the firmware as well; initially the unit worked fine...now after a few days it won't power up. 

I purchased the unit new about 3 months ago and it had been working fine - it's only been used in my home studio and one gig. I'm running Serato DJ 1.9.1 on OS X 10.11.5, FWIW. 

Is there a way to reinstall the firmware in spite of the unit not wanting to power up?

The firmware itself wouldn't have caused this -- if your unit powered-up at all after the update, that would rule out the firmware.

Have you tried swapping the DC power adapter with another?

It seems the power adapter isn't functioning properly; picked up a multimeter at Home Depot and tested it out. Seems unusual that after owning this unit for 3 months that the power adapter would go belly up - is this a known issue? 

@Jeremy > Glad you were able to sort it out, and no, they generally don't fail that soon. I'm not sure if the power supply is covered by warranty, you could try and contact Pioneer DJ technical support regarding that, but I'd recommend having a spare if you're gigging out.