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

Wow, those 3v 50.2’s must have a really low forward voltage. Will 30Q cells be able to handle 12k lumens, without sagging too much?

Hi, I’m having an issue with my BLF Q8 and I’m trying to find out if there’s anything I can do to fix it or if I have to return it. I’m not technical with torches, but I’ve been reading posts, manuals and guides to try to figure this out.

When ramping up, it stops at a fairly lowly level. If I continue to hold the button, it still double flashes after the amount of time it would normally take to reach full brightness. When ramping back down from “full” brightness, there is a delay until it reaches its limited brightness level and then decreases to moonlight as normal. If I stop ramping while it is below its limit, the button flashes only once. If I stop ramping while it is above its limit, it flashes twice. This makes me think the FET channel is not working.

I’ve tried doing a factory reset from the version check mode. It does the rapid flash to confirm reset has occurred but it continues with the same behaviour.

It was working fine yesterday. This issue started after doing the latest recharge of the batteries. I’ve used it on and off over the last 6 months since I bought it with no issues. I bought the batteries brand new at the same time (Samsung 30Q 18650 button tops).

The only other weird issue I’ve found is the battery indicator seems to be reading low. The freshly charged batteries each read 4.2V in my charger (XTAR VC4), but in the torch it indicates only 3.1V.

Any suggestions on what’s wrong and what I could do to fix it? Or should I just return it to where I bought it? Or should I be asking elsewhere?

Thanks

It does sound like the FET has stopped working and your only running on the single 7135, so maybe 150 lumen max. A video to show what your describing would help, but I think I understand you.

You can try a return or warranty replacement, but I don’t know if they will do anything since it worked fine for 6 months.

With a bad FET, you can buy a new FET for a few dollars, but you need hot air to swap it.

You can also buy a complete new driver here for about $10 usd. You will need a soldering iron for the led wires.

I’m curious if others also think it’s the FET. The battery thing is strange. With fully charged cells it might read 4.1v, but 3.1 is strange.

dunno about the battery voltage readout, but the ramping behaviour sounds efinately like the FET not working, or the trace from MCU to FET not making contact. First try could be soldering some extra solder to the legs of the FET and perhaps the leg of the MCU that goes to the FET-gate. That tests a possible bad solder joint that originated over time.

Check the batteries with a DMM (digital multi meter)?
I’d first try and eliminate all of the possibilities that don’t require soldering myself

I don’t actually think the batteries will be the problem but it’s best to be sure

Also check the battery control contact with the brass ring. I had a set of batteries that I used and only one worked. I rearranged the batteries and tightened fully they all were in contact, it worked fine.

I wouldn’t bother messing with the FET or getting a new one. The incorrect voltage readout indicates there’s more to the problem than just a bad FET. Get a whole new driver, or new light.

What is the difference between this and the Sofirn Q8?

The BLF Q8 has a more neutral color temp and more lumens, in exchange for less throw.

The Sofirn Q8 throws farther due to its domeless LED emitters.

@mike89
short answer is:

The BLF version uses 5000K neutral white emitters. made by Lumintop“Thorfire”
the Sofirn uses ~6000K cool white emitters. made by Sofirn.

Corrected. the green “T” button looks at me every night… :person_facepalming:

Correction: the BLF version is made by Sofirn also, under the name of Thorfire.

The emitters. Thorfire Q8 uses xpl NW, Sofirn Q8 uses xpl-hi CW. The Sofirn Q8 has a smaller hot spot and more throw.

Was #1469 pre-order.

My beacon switch led stopped working. Any fix or replacement parts for it?

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?