Nokia :: N95 8gb Slide Up Phone To Write Sms / Screen Went Black Like Negative Photo

i have an nokia n95 8gb.And i have a problem with my screen, one day i slide up the phone to write an sms, and instantly my nokia screen went black like a negative photo, and i turned off the phone. When i turned on the phone, the phone screen didnt give any signs of working, but the rest of the phone was fine, the lights turned on and stuff. I could work with the phone without looking on the screen. But in the next day i went to nokia care point and they looked to the phone, and they told me that was the ribbon flex . I bought a ribbon flex to my nokia and replaced it yesterday, but the phone is in the same situation, the screen does not work and the rest of the phone is fine. I ask if someone can help me with this.