Yamaha dx100 vintage 80’s synth for repair - $40 (Verona)

Yamaha dx100 vintage 80’s synth for repair , the power is on and it has a red, blinking light and on the screen is 4 black squares and it doesn’t make a sound, now the screen doesn’t appear to be bad it says if it’s a code for some thing, I have walked online and people have successfully repaired them, but it’s not on my pay grade.
$40