I recently bought a MOX8 sight unseen for a steal at $100!! Only to find out later that there is something wrong with it!! When played the sound "crackles". I took it in to my local music store and they had it for 2 months and had no idea what the problem was. The recommended that maybe the main board was bad. The key word "maybe"!! The part direct from Yamaha was $636. Even if I pay the $636 I will still have a really nice synth for a pretty good price, but if it is not the problem I am out $736!! Any recommendations before i buy it?