*Fixed*
I had the F error for a few weeks, was going to try Blake70's method, but decided to look inside first.
Unscrewed all (*) screws from the black and blue parts of casing, and removed it.
The parts/capacitors looked good, and there was no apparent dust. There was, however, a chip (Processor?) labeled "Miam Voicelive v1.3" My friend had a computer issue once where he removed the chip (Obviously off and unplugged) and reinserted it, to find the problem gone. I did just that, being as careful as possible, then reattached the casing. There is no more error, and the unit is fine.
If you try this, it may void the warranty, and I am not sure the exact precautions you should take, in case the chip might "fry" like RAM if you are not grounded. It worked 100% fine for me though.