small red lights flash on my Nakamichi PA-7


First time on this forum.
Just bought a used Nakamichi PA-7 power amp. Everything seems fine, music sounds great, but sometimes the small red lights on the front of the amp blink or stay on for a second. What does this mean? Any suggestions on where/how to find an owners manual for this unit.
Thanks
Joe Sullivan
joestoy
THANKS TO EVERYONE, some very interesting info for me to use. The speakers are Vienna Acoustics' Baby Grands, my brother-in-law didn't use and sold them to me.
Any ideas on where/how to find operating manuals for the Nakamichi PA-7 and CA-5.
I was playing very loud Highlands Cathedral, a combination of brass, bagpipes and organ.
Again thanks to everyone.
Joe