I Got A Friends AUDI A4 Tdi YEAR IS 2000, ITS GOT Magneti Marelli Cluster But Some Guy Was Using The Vagtacho On It And Messed It Up..Its Now Displaying A Row Of 9’s Where Original Miles Are Displayed And Will Not Start ,the little spuare computer screen is now wonky and faded and it is Immobilized..
HOW DO I GO ABOUT FIXING THIS FOR HIM
Any advice would be appreciated

Thanks