ARC repair needed

I tried swapping both input leads and outputs to speakers.  I tried reverse on the preamp and inverting in the amp.  It’s always the same output.  I suspect it’s either a solder or a capacitor.  

You can use freezer spray to check for cold joints.

High End Audio Repair in Phoenix is great.  James is the owner.

shipping power amps always an issue, for risk of damage as well as cost

george meyer av in downtown la is your best bet

I live in Los Osos CA next to Morro Bay. I got a great tech that'll fix pretty much anything. He doe tubes to solid state gear. There's my other tech who works in LA about every other week ( southwest airlines at LAX) who drives down and works 2 days at a time. He usually takes stuff for me down or back up. 

Search Pioneer sx-1250 in the Torrance Craigslist and you'll see his contact on there.  there.