Yellow light of death to blinking red

Just used the YLOD repair kit. I put everything back together (going backwards from step 41, per the instructions). Upon power up, I get a quick green/yellow light into 3 beeps and a blinking red light. No real idea what is happening here, I'm hoping I just need to retry the solder-reflow, or check on one of the ribbon connections. Anybody run into this one yet?