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

Before I powered up my long dormant Pioneer SX-1050 I found a current limiting device on eBay. It used a light bulb to someone limit current. It powered up OK. I then used a multimeter to check for DC on the speaker terminals. Luckily there was none. 

Yes, good advice about checking for DC with a multimeter.  Unlike a tube amp with output transformers, some solid state amps can pass DC.

I’d contact Pass Labs. They may tell you to run the amplifier through a variac in order to allow the capacitors to reform safely. Best of luck. 👍

Just curious: How did you end up coming upon an unused for 20 years boxed up amplifier?

Many years ago I rebuilt a handful of very old (circa 1870-75) Acoustic Control Corp. solid state guitar/bass amplifiers.

I had this same question. Yontz, at Mad Scientist Audio (? - been a long time) suggested using a light bulb current limiter, basically a light bulb socket spliced into a short extension cord with a 60 watt bulb.

NEW electrolytic caps AND old, discharged ones appreciate slow voltage build-up. Worked like a charm.

Lately though I use a 20 amp variac on recapping projects. ADCOM preamps, amps, tube amps, 1.5 kW HF linear amps, etc.

Curious to know what you do and how it works out for you.