Had this in my Avengers. You will also get dead pixels sometimes. Not much you can do if the game is out of the warranty period expect buy another display or try soldering in some new display blocks where the lines are showing up. This is a common problem with the LED DMD displays.

I recommend the ColorDMD, it looks amazing.

Unfortunately the display may be going bad.. I know I had one replaced under warranty on my stern..

Looks like a good time to buy the ColorDMD.

Stern's block LED displays suck for reliability.

You can have the block replaced I think it's the one right before the dead pixel and it will fix it. A stern distributor can order this part for you I think they are $11.00 also my distributor told me that the dmd's were covered for 2 years

You can alternatively go for a SmartDMD system (google it in pin side), that will set you back approx 50-60% the price of a colordmd but will require some more DIY

There is a line from top to bottom. I don't think that is caused by one block. It is more likely a wiring or electronics problem but I could be wrong. Maybe I am wrong since I do see a pixel out in that vertical line.

I've had display issues like this on many of my newer Sterns (MET, AC/DC, TRON). It's a bummer. Considering they are being used very infrequently in a home, I can't imagine how long they would last in a commercial environment.