ZPE repairs and Upgrades

I recently repaired ZPE professional Power amplifier boards (ZPE 500 and 1000) sent from Australia. The owner sent the boards and output devices so I could fully restore them (and add some performance enhancements). They were returned and are now back in their chassis and fully operational. I also did minor repairs to a local ZPE 1000. I was presently surprised at the ease of repair and that they all performed as if they were new boards! No Significant drift on any of the settings.