Help!!! S500i display problem...

I just bought an original LCD replacement for my S500i. It works fine but the only problem is that, when i'm not using it for about an hour or longer, the LCD display turns white (blank). When i turn it off for a few seconds and turn it on again, the display backs to normal and after long period of not using it, it will turn white again.

Here are the solutions that i've already done....
* Updated the firmware version using SEUS (Sony Ericsson Update Service)
* Flashed my s500i to w580i using these files...
W580_R8BE001_MAIN_GENERIC_LA_RED53.mbn
W580_R8BE001_FS_APAC_RED53.fbn
HB1-06_Gen_CDA102568_101_R8A_GENERIC_APAC
I also tried other versions but all of them failed. I still got the same problem.

I don't want to turn my phone off and on evrytime i'll use it so please help me with this problem.
Every help will be highly appreciated. Thanks in advance guys! Godbless.....

change flex (mainboard to frontboard connector) and your problem will be solve.

Thanks mate! Appreciated. I'll try to purchase one. Hope this will solve my problem. Feed back soon!