Mitsubishi Repair Problems? Ask a Mechanic for Answers ASAP
Unfortunately there is nothing really external that could cause this behavior, only the MMCS would be suspected at fault here. Even if you had a weak connection on the back, which you could certainly check, it would be more probable that this would cause the unit cut out entirely rather than fade in and out.More likely here is that the panel is dying on the unit and will require replacement.Mitsubishi does not offer any service parts for these, only complete replacement which is extremely expensive. If you want to fix it yourself, the best bet would be to locate a used unit on ebay.If you are wanting to keep costs as low as possible then your best bet would be to send the unit out for repair to determine exactly what is wrong with it and the parts required to fix it. We use H and R Radio in PA for just about all Mitsubishi radio repairs in the eastern US, so they would be your best bet as far as sending it somewhere that it intimately familiar with the unit and less likely to have never worked on that specific model before and potentially end up costing more money through incorrect fixes.If the repair costs end up being terribly high, of course you only have your diagnostic cost and shipping to worry about and can still go the route of a used unit (or switch to aftermarket etc).