Can Anyone Recommend a Repair Shop for a Yamaha C-2x Preamp?

I have a Yamaha C-2x preamplifier I purchased new through the Post Exchange system in the late 1980s while stationed in Germany in the US Army; for many years, this was the preamplifier in my stereo system.  It has been "brought out of retirement" to use in the second system made up of my older equipment in my office.  It is in very good cosmetic condition and has not been abused in any way, but the left channel has no output, which is not surprising for a piece of equipment that is about 35 years old.   I suspect that, as a minimum, it will need new capacitors.  Can anyone recommend a reputable repair shop to repair this unit?  Thanks to all.