Parkavebrewco

Hey there, so I got a Spyhunter upright from a forgotten storage unit awhile back and took it home and boom! Plug and play. After a few sessions the screen starts acting funky( everything gets all squished vertical) so I stop playing it. I came back to it later on and when it turns on all I got was a screen full of explanation marks with an alternating blue/black background. Then blank screen on some other boot ups. No sounds for either. I replaced the ground plug and blew the dust out of the inside. Everything seems to be in ok shape. No battery leak or burns on any boards that I see. Looking for some advice as this is my first machine. Can get pics if it helps. Thanks!