Marantz 2275

I picked up a Marantz 2275 receiver that is in very good shape. I was wondering if anyone has a source for either modifying the receiver to increase performance or to simply do a "check-up" on this 30 year old receiver?

Thanks for the help...
Contact audiogon member "Ezekiel".
Try looking over at I believe there are also sponsor banners for repairs, etc.