Pioneer out of mothballs.

If you mean an SX-1280, no.  It does not accept a digital input.  You would have to run a 3.5mm to L/R RCA connector from the analog audio out of the computer to the auxiliary input of the receiver.  Good luck & happy listening!

I tried this from Amazon Tendak Digital to Analog Converter Adapter Optical Audio 2 TOSLINK SPDIF + 2 Coaxial to TOSLINK with L/R RCA and 3.5mm Stereo Audio Switcher, but I sent it back not trying the 3.5, only the 2 coaxial. Maybe shame on me?

Thanks eff for your response,it was very helpful. I re-ordered another unit w/3.5 to rca cable, lets see if this works.

If your unit had long been sitting in hibernation, than you will need variac to power it own slowly. It's not tube unit, but nevertheless, first, I'd open the top and bottom covers, sweep it with clean paintbrush and/or vacuum, spray the whole thing especially rotary switches, all pots and knobs with DeOxit D5 (you may add F5  formula on mechanic components such as rotors of tuner and rotary switches ball bearings), than connect unit via variac and step-by-step increase voltage every 10...15 min to operating voltage. I usually do that within 3...4 steps i.e. within an hour towards the operating outlet voltage. Than I keep it running for an hour. SX-1280 has stand-by load resistors so running it unloaded isn't an issue -- just make sure that receiver is ON, but all speakers are OFF.

Thanks czar for your suggestions. I did clean it top to bottom, all the buttons,switches & knobs were cleaned w/CRC 2-26. I took the time to check for any cracks in the circuit boards & all the caps are fine. All the RCA plugs were also addressed.  Unit is as it was new. The only thing is that I didn't lube the dial knob & tuner assembly. I didn't know what to use.Any suggestions? I also didn't use a variac, all is working fine. I love this thing!
  

On tuner dial knob I'd use DeOxit F5. It's a lubricating formula.

That's what I used. Thanks. Now if I can get better FM reception I'll be a happy camper.

It has nothing to do with better FM reception.
For that you may need external antenna.

I always had an outdoor antenna since I bought my SX-1250 new in I think 1976. Then sold that to make way for the SX 1280, saw no reason at that point to purchase the SX-1980 if you familiar with those models. Lived in Bklyn,NY reception was great there. Then move to another NY borough again, no problems with an Archer Fm antenna. Now I live just out of NY in NJ & my reception is only fair at best. Inline to NYC to my home are obstruction like power pole & NJ transit, which has an overhead power line to power the Train. Installed are an Magnum Dynalab - ST-2 FM Antenna with an 36 db FM signal amp. I stream internet music thru my computer w/Creative Sound blaster sound card to my Marantz 7702 ii via SPDIF, finally out to my B&W 804/803. Steaming music thru my comp sounds way better then just out of the Marantz. The music from that Marantz apposed to the Pioneer is no match by any means. Also the SX-1280 feed my Klipsh Heresy ii. This is why I'm trying to connect the Pioneer. :(