Wrong, Wrong and wrong. Never clean a BD or DVD laser with a Q-tip and/or methylated spirits! (They have a special lens coating, without which, they burn-out quickly, not to mention the way they are carefully sprung to respond to the driver EMR/EMF, any pressure at all will stretch the lens-mech, giving u more errors down the track)
This error is a general HW error(often BD, but can be BT or others), the guy quoted in the post above only managed to 'fix' his because it would have been a power related issue (eg; backup Battery) If you can't afford to have it fixed by Sony, then send it to a local QUALIFIED professional (who specializes in game-console-repair) they will do it cheaper than Sony and tell you the exact cause/ Messing around with these other things will at best amount to a very lucky fix/waste of time or at worst will damage something that makes it more expensive to repair in the long-run.