Q8, PMS SEND TO THOSE WITH ISSUES BLF soda can light

Replacement switch $3.01 at Aliexpress

https://www.aliexpress.com/item/32879434650.html?storeId=2933049&spm=a2g1y.12024536.productList_2692165.subject_15

It took me a long time to get around to it, but I bought a new driver and that fixed it. Thanks for your help!

:+1:

Does it say the correct voltage now?

Yeah that’s fixed too!

I got my BLF Q8 in the original group buy, and it has seen some use from time to time. Mostly camping and emergency light at home. I see there’s now Anduril firmware for it. Is it worth learning how to flash / getting the hardware to do it?

Do you like Anduril? It has it’s pros and cons. If it has a feature you really want then it might be worth it.

Hey all,

I picked up one of these a few weeks ago and it worked great until the most recent time I pulled it out. I don’tt see any damage but it is not powering on, even with fully charged batteries.

Would anyone have any suggestions?

Do you get the double blink when screwing on the head?

Are you using button top cells?

What cells are you using?

I do not get any blink currently.
I’m using Samsung INR18650-30Q button top.

Okay, with no blink it either means the driver is not getting voltage or the driver is bad.

Let’s focus on the voltage. The end of the battery tube needs to contact the driver ring so make sure these contacts are clean. Then make sure you are screwing them together fully. Maybe remove the o-ring to make sure it’s not getting in the way.

Maybe try using one charged up battery.

You can feel the spring tension when screwing it together, right? The springs still have tension?

You can also try cleaning the battery ends and the driver contact ring just in case.

Check that the driver retaining screws are tight.

Also check that the driver is sitting flat like below.

Make sure the O-ring wasn’t sticking out and got clipped when screwing it together.

Make sure the cells are in fact fully charged. (Test under load in a separate light, not just on a voltmeter.)

Crank the crap out of it when screwing it together, to make sure it’s making contact.

Check the mating surfaces to make sure they’re clean. Especially the edges of the battery tube.

Eyeball everything, like the main contact ring (scrub if necessary), the springs, everything.

Unscrew the tailcap and lookit the board underneath, see if there’s anything obviously wonky (missing screws, burnt traces, anything).

Give it the rattle test. Shake it like Hell in a quiet room and listen for rattles or anything loose inside.

That should keep you busy a while. Lots of those problems can be fixed with basic stuff like the above.

Get some conductive lubricant (“bulb grease”) and wipe all the threads and battery contact points clean and leave a bit of grease in the areas.

You do that? I’ve never done it.

And again: “Bulb grease” is not conductive. And don’t put any conductive grease in a flashlight, it will make things worse eventually.

Why’s that? I thought conductive grease on the bare aluminum parts would be good to improve conductivity.

The connection is made at the contact points of the metal surfaces. With high voltages there might be arcing through the air which will cause all kind of issues. Thus you can use “bulb grease” which fills the space with a better dielectric to prevent arcing. But that’s nothing you will find in flashlights. It also seals the metal surfaces against air and moisture to prevent corrosion.

Using a conductive material will not improve the resistance. You would need something like liquid metal and also consider the resistance at the points of contact between the aluminum and this other metal. The biggest issue with any conductive non-solid material is that it will eventually cause short circuits because it will reach places where it doesn’t belong.

Lubrication in flashlights is used to increase the lifetime of the threads and o-rings. Aluminum on aluminum can be very abrasive and tearing on the o-ring can prevent a proper seal. It will also help to seal the flashlight against moisture.

Also keep in mind that aluminum oxide is an electric insulator. When you screw the threads together the forces will break the extremely thin layer of aluminum oxide.

From what I can see, the contacts are clean, springs are clean and tight, edge of the battery tube is clean, o-ring is properly seated and I don’t hear any rattling.
I used a pencil eraser on the main contact ring, cleaned away the eraser dust, then wiped it with a rag and a tiny amount of Ballistol, then wiped clean.

I haven’t taken anything apart besides opening the battery compartment and rear tailcap but don’t see any obvious signs of scorch or anything loose.

I don’t have another 18650 light but I ran the batteries through another charge cycle to full.

It was just riding in my backpack, so I’d be surprised if it suffered any major shock or impact since I’m not rough with the pack since it has a lot of other stuff in it.

Thanks for the help so far.

Ballistol reacts with copper and partly dissolves it. The traces on a PCB are a very thin layer of copper. So please don’t use ballistol on PCBs.

I’ll remember that.
It was just a drop on a rag and only applied to the contact ring but I’ll be careful to not do it again.

Did you try removing the o-ring and fully tightening?

Since you are new to 18650 cells, can you confirm the positive end sticks up above the plastic wrapper? Some people use flat top 30Q because it just barely sticks up and sometimes it makes contact and sometimes it doesn’t. With button top cells they add the button which raises it about 1.5mm.

It seems logical the charger is working and the battery is not completely dead, but to be sure do you have a voltmeter to verify?

Other than this, it seems the driver may have gone bad. Can you solder? You can get replacement drivers for about $10. You can unscrew the bezel and driver, remove the screw that holds the reflector into place and then check the led board (mcpcb). It’s possible a wire may have come undone.