what is error F61 16 for Panasonic SA-PT560 sound system?

I finally reconnected my sound system after it has sat idling for 4 years after I moved
When I try switch it on it sounds like when a battery is almost running empty, every consecutive attempt is less and less
The code I get is F61 16
I have looked it up and opened up the system and used a hairdryer to blow out all / any dust etc, but it still does not want to work :'(.
I do think it is the fan because after using the hairdryer it didnt work so I thought perhaps because the blown air caused the fan to turn the wrong way around, so I put the vacuum cleaner on the outpoint and had the fan run the correct way, and then I got a spark of life again :) and again the error F61 16
I am a bit technical but not that much that I feel comfortable taking it apart and replacing bits. Can anyone advise anything else please?