My A&H ML3000 has 2 or 3 channels where the mute lights will sometimes get "stuck" on, despite the fact that the actual mute functions as it should. One strange thing about it is that sometimes if the board sits out in the sun for a little while it will behave as it should. The board functions perfectly otherwise, but this is annoying as you might imagine. Has anyone run into this? could it be dirty contacts in the switches themselves? I haven't had a chance to tear into yet and spray some contact cleaner if possible.