Grey screen nes

Yoshilime M.R.

Master of Limes
Today, i bought a nes, tried it out, and gave me a solid gray screen. cleaned. Asfault screen. pin-fixed. black added with white screen. in all my experience fixing nees's, i cant figure out the problem. please help.
I've seen NES's flicker, flash purple and white, turn blue, turn black and white, but never a solid gray. Strange.