Camera is always detected first. Never seen a bad camera interfere with iPhone function, so doubt doing anything with camera will change anything. Fix for White Screen is Hard Reset. Hold together Home and Power buttons for about 15 seconds until iPhone restarts. Hopefully then screen with be normal. You could always try a system restore in iTunes. I guess it would not hurt to try and reseat the LCD connector to the Logic Board. If still White Screen then LCD is bad or Logic Board is bad. Either way your iPhone is in a very bad way, because the repair will be difficult and not financially worthwhile for an Original iPhone.