Hi there, I had a similar problem with one of my PFM-500. The error code states that its a power failure. But it was a transistor on the Plasma boards that had failed. Replaced it for 1 USD and got it working great! Nice monitors by the way. It could still be a PSU failure for your part, but most probably its something else that have failed. I have four of those monitors, and only one was fixable. The other ones have tiny cracks in the plasma itself, and only hummes quietly when trying to start.