Hitachi AV3000E tuner/media box

[markjd]

This is the media-controller box that comes with several of Hitachi's plasma displays, including models 32PD3000E and 42PD3000E amongst others. They have a habit of going bad with a specific fault, where the controller box and display will switch on fine so long as they're not connected together, but as soon as the cables are linked up the controller box clicks on and off continuously, and the screen never displays a picture. I've heard this was a bit of a design fault, and Hitachi have some sort of upgrade kit that needs to be fitted in the controller's power-supply which usually cures the problem, but I haven't been able to track down a supplier. Does anyone know what the kit consists of, or what else could be causing the problem?

thanks in advance
Mark