If ever encountered a Nokia 5220 Display problem issues like white screen, blank screen, blue screen,saturated and garbled display problems.The very first thing you should do is to replace the LCD screen module, restore or update the device flash firmware. But after doing this procedures the display problem still exists and nothing happens.
This solution below might possibly help solved the problem for it shows the display data signal line paths from the processor chip through to the LCD pin connector for an ease of troubleshooting.
Each of the display data signals which feed from the application processor chip is filtered by a 330 ohms resistors before it reach up through to the LCD screen display module. You may start to check, trace from this components and way up to LCD pin connector.