Help Screen replacement issue

[Spec-Kie]

i have a s3 thats just had a screen replacement. the screen works the touch works every thing works but all of a sudden the lcd will go black. touch will still work and the sound will still work. then after a bit it will come back on again. any idea??

 

[Rukbat]

Bad replacement job. Let them try again.

 

[Spec-Kie]

Bad replacement job. Let them try again.

Would you care to elebarate on that one please? as i fitted the screen my self?. There doesnt seem to be any niks in the flex or any thing? does it need re fitting ?