Suggestions for testing a never installed, 20-year boxed amp.

Buy a Chinese variac on eBay for around 100$. Power up slowly over 24hrs. Make sure you get the proper amp variac. You should be ok. Good luck. 

All good ideas. I'll try to contact Pass Labs Monday before doing anything. I already have a lightbulb current limiter setup, a variac, and some 250W 8ohm resistors.

My acquisition of this amp is a long story. The company I worked for, at the time, set up a number of QC stations and 3rd eye approval stations for mastering DVD movies for major studios. This amp was never used in any of the setups. It sat in the shop for years until the US operation was closed. I purchased this and some other equipment from the company before moving on. My plan was to set up a better home theater system with this amp. I also purchased a new Marantz AV7005 that's also still in its box. Basically, I couldn't find speakers that my wife could live with. Now I'm trying to decide what I should do with these items.

I'll let you know what Pass Labs tells me. Thanks again!

I think the advice being given about contacting Pass Labs before powering up is sound. Not being familiar with Pass equipment, is there any current limiting circuitry in them? I have a Mark Levinson ML335 that's been boxed for 25 years or so. When I asked a similar question here about powering it up, it was recommended I send it to a shop to have the capacitors checked first. I found a shop in Austin (Pyramid) that I'll be sending it to BEFORE I put it in my system.

Incidentally, I had occasion to visit my daughter in Austin recently so took the opportunity to visit the shop. I was very pleasantly surprised at the facility and evident expertise available. 

Good luck waking up your amp and as always...

Happy listening.

Pyramid does good work. And they are a Harman authorized servicer.

I used a Variac and 2, 8ohm 10watt resistors on the output with volt meters across them.  Short the inputs.  Take the covers off.  As I easy up the variac, I watch the meters, sniff around and look for smoke.  Now I would use an infrared thermometer.  Before I used to use my trusty finger.  Hoping B+ doesn't get me.

I had a laughed watching Vice Grip Garage.  When he connects a battery to a car he's resurrecting, he sniffs around and looks for smoke.