Yes that’s pretty much what i was asking. Sorry i’m tired. Should go to bed. But yes i really like the way the s70s is setup like that with the tail switch as a lock out.
The tail end contact has a spring, will clean the contacts on the positive end too, and try again.
Thank you!
Not a problem SD_Trojan 
Thank you Jason,
Just making sure I understood correctly, so I remove the tail cap and use a battery, connecting from the negative end to the exposed tail end and fix to the threading maybe?
If this alternate connection works, how can I make it to a more permanent set-up, screw the tail end back again?
The S70 seems to have come out in early 2016 and the L6 in mid 2016.
The tail switch controlled on/off and side button only changed modes.
The S70 was updated to the S70s in early 2017. Now the side switch controlled on/off.
The L6 has had no upgrades. It is over due.
Sofirn is working on their version with a slightly bigger head, SMO reflector and xhp70.2. It may even have double the lumens. It’s called the SP70 if your interested.
We are not trying to fix it yet, we first have to diagnose it.
The problem could be in many areas so we have to narrow it down. In case there is an issue with the tail cap, we can temporarily bypass it to see if that makes the lights start working. If shorting the battery to the battery tube doesn’t make it start working, we move on to a different area.
The treads should be anodized so that won’t work, the wire needs to touch the bare metal part of the battery tube.
On your EBL batteries, did you add a solder blob to make them work? They don’t appear to have raised ends.
Here is a picture I found.
Notice where the wire touches. It needs to be raw metal.
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