[j209177]

I am helping a friend fix a SL-253 with a MSG-501 control.

The first thing you notice is the colors shift and fade in and out when doing nothing. Then when scrolling thru a program sometimes the screen will stop scrolling and what the cursor is on will change characters.
So I think the screen is going bad and I took it out to look at it. I didn't see anything bad. I took some pictures to order a new screen. Then he wanted the machine back together to run some parts.
I put it back together, and it wont boot properly.

It says
Goplib.dll : DosOpen() faild (110)
[C:\GOp3]

Any idea what the problem is?