The control board for the AC water pump on my 1990 39 Express needed replaced the water pump for the AC was not working when the AC units demanded it to turn on the pump. Most of the replacement boards found on most sites cost around 300 dollars. Micro Air had a replacement board for 98 dollars. The board has been installed and works just fine. Also Quicksilver generator needed the board replaced and the voltage regulator board checked. Flight Systems Inc. Will check and rebuild the Quicksilver Generator boards. Tom at Flight Systems said he was familiar with these boards and has rebuilt them before. In inquiring as to what he thought about the Quicksilver Generator Tom said he found them to be a very good unit.