No power to control panel or pumps and heater.

Had this same problem several months ago, lost all power to system. Repaired that and then board shorted out. Replace board and everything worked for about two weeks, checked it one day and nothing. Done all the checks fuses, etc. Have power to panel but nothing going to pumps, control panel or heater. Removed the board to check forany shorted or burnt spots, nothing. Any one have any ideas of what to check? When the control panel (heat and pump control) is unpluged a buzzer of sort goes off if this make any difference.

When you tested the fuse especially the main system fuse did you remove it from the fuse holder and check continuity? That is the best way to test a fuse and want to verify that you didn't check it while it was installed.