Found this recall reposted on another site: http://www.overclock.net/sound-cards-computer-audio/939032-warning-dayton-subwoofers-recall-amp-recall.html This link shows how to take out driver to check serial number: http://www.parts-express.com/pdf/HT100-120_Amplifier_Procedure.pdf The instructions show taking out 4 philips screws. Mine which is about 3 years old had 8 hex and the SN was much lower.