I have 2 Lexicon MPX100s that are misbehaving, both doing exactly the same thing. On power up, all indicators light up and the unit freezes, with no response from button presses. Powe cycling doesnt help ... they just repeat the same thing and the units are unusable. They used to do this intermittently before, now it appears to be a permanent problem. Has anyone encountered this? The power adapters are ok and appropriately rated for the devices. Any advice on what to do? I have decent soldering and repair skilss and dont mind opening up the units to attempt repair. Please help!