Sooo in borderland pre sequel. Mission “find signal source” I get to red bellys main gate… And nothing. I kill the few grunts by the door and ontop of the waypoint and the gate doesn’t open?!? I’ve played the game through once before??
I can’t progress without doing the mission?!
this happened to me as well, unless you can open the gate you wont be able to find the signal source even if you jump over the wall. I had to join someone elses game when they were on this mission just to pass it.
Yeah this is so frustrating. There is no games available when I’m on which makes it impossible to get past it!.. Ugh…
Is it the gate where RedBelly send out a couple waves of guys at you, and there’s the whole “she wasn’t a badass”; “yes she was” exchange? Or is it the one earlier where a badass mugger comes out after you defeat the elite jet pack guys?
If it’s the latter, you can grenade jump over that and then loop through the building backwards to trigger the waypoint. If it’s the former, yeah, find someone else on that mission. Best of luck to ya.
Yeah the gate before the elite jet pack guys… Trouble is there is no games abvailable EVER so never gunna get past this 
I am presuming that you are referring to the first gate where the turrets are. This gate has always been problematic for me.
The mission wants you to kill the gate guards after you kill the turrets and the gate opens. The mission does not proceed if you do not do this. You can go all the way to Red Belly but the mission is still locked at the first gate.
You need to kill 4 gate guards. Sometimes only 3 spawn and you will not complete the task. If you look on the mini map there will be a circle on it at the gate for the mission area. This needs to be cleared.
If it doesn’t. Travel to Triton Flats through the travel gate behind you and back again to save the respawn point. Then quit and reenter the game to restart this part of the mission. I usually don’t use my action skill at the gate as using it often results in failing this part. It never fails when i don’t use it. (I have done this many many times with multiple characters)
Good luck.