Graphics ploblems with SC-3000

Hi guys again. I'm having problem with this sega sc-3000 it have some lines in the image (check the pics) and for what I read it might be a vram problem. I have checked the board and fix all the problems I can see. Everything works fine except that line. The board have 8 ram chips and I need to know which is the faulty one.

 

That does indeed looks like a ram problem. You might want to check for cold solder points too first. Check around the cart edge connector, TMS and other chips. Also, I once had a similar problem although with a SG-1000 system, and it turned out to be the leaf switch pause button.

 

I reflow every solder point and add solder to those that looks suspicious on all chips on the board to make sure it wasn't that, also to the cart connector. The cart connector is also clean. It must be one of those IC but the question is which one.

Edit to update: It was indeed a faulty vram based on the lines of the screen I it was addressed to IC17. Change it now works like a charm.