Black screen but digitiser works

fone had been water damaged and after thorough cleansing and soaking with Iso Alcohol and replaced battery, and installed new charge port assembly, cleaned all connecters and ensured they were seated properly, now phone powers up,is recognized by Itunes, responds to charger, voice over functions and digitiser responds(concluded after feedback from Voice-over when touching the screen) but the screen stays black. Is this perhaps a failed LCD or could something else be causing this problem? ANY information would be helpfull, Thank You