I don't know, and neither did the Pioneer agents that visited to inject a replacement firmware. My Kuro did buzz, but worse than that there was an about even chance that an evening's viewing would give me a bad headache. After ~300 hours I exchanged it for a V10, which hasn't induced any headaches. Neither Kuro or Viera noticeably flickered (that it to say that that there is a shimmer on the V10 firmware update screen but none with solid colour test patterns, etc.).What was wrong with your Kuro?