Thanks Darren, I just read about the plug in the centre on the net, before you posted your reply.

I was able to get that plug out, and I put in one drop of sewing machine oil, and cleaned any moisture. I spun and blew it around a few times, dried it again, reinserted plug, put sticker back on and reinstalled the fan on the motherboard power supply.

Started it up, and YIPPEE, it is as quiet as a church mouse now.

many thanks, and I hope my newbie repair helps others.