Modpacks dont work

[ShadowHunter462]

Hey guys, so whenever I go to launch either of my downloaded modpacks (voltz or tekkit Main), after running all the minecraft assets and stuff the launcher closes as if it about to launch but then the technic launcher comes back up and nothing happens. I did some research into it and found a video that suggested that it was my graphics card that was the problem (Nvidia Gforce 940MX) and i downloaded something that changed something so that I could play but that didnt work. So I watched another video saying that it was because Technic launcher didnt work with the latest version of java which i have (java 8) and told me to downgrade to java 7 but when i tried to do that it said that java7 is no longer available for download. My computer is a Acer Aspire F15, Specs: Intel i7 processor, 16GB DDR4 Ram, Nvidia GeForce 940MX graphics card with 4gb dedicated vram and 1 tb hard drive. If some could help that would be HUGELY appreciated, ive been trying to find a fix for a while now and getting really frustrated because everything ive tried doesnt work :(. also my mate has the exact same laptop but just a little less ram and he can run it fine no problems (he got it as a gift from someone so someone couldve done something to it before he had it that made it work)