Trouble fixing gears

[dhat90]

Hey, i hope this is the correct subforum

The bike gear cables broke and Im trying to replace them. BUt it's my first time, and I've run into some trouble. I can't seem to get the correct tension in the cable, or there's something wrong with the thing thats supposed to shift gears. I took a video of it. The same tension works for two different positions in the gear shifter thing. How do I fix this?

[Painkiller]

how about a still shot of the bike in normal position of the rear cluster/chain and derailleur. also a pic of your shifters.
I do not know why you are pushing on the derailleur with your hands. It also looks as if the chain is not routed correctly.
You would also be better to hang the bicycle in some fashion in the normal upright position while working on this system