EGPU and blackscreen. I need help.

Hello. I bought the exp gdc 8.0 dock and tried to use it on my laptop but i get a black screen and my monitor does not receive any signal. I looked into it and tried the ATX switch, the delay switch and some changes in the bios, but nothing seems to work with this laptop. The fans start spinning and the screens are black. i tried the setup with an older lenovo laptop and it worked so the hardware seems to be functional. but i was getting a huge bottleneck with this laptop. I think that the next step is to look for a modded bios for my laptop which will allow me to use the egpu setup, but unfortunately I have no knowledge in this field. maybe somone can help me .
Laptop: Asus fx503vd
BIOS version: 308
GOP version: 9.0.1067
EC version: R1.13
Thanks.