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

You guys rock! I’ll check on lunch break!

//factory reset did not fix my issue… looks like she is dead jim… :frowning: on to ordering a new one. oh well gives me a reason to break it open and flash newer firmware as well.
Neil

Are you sure the factory reset worked, meaning it did actually do the reset? Think the earlier v1.0 firmware didn't support it, can't recall though. It's odd because I got a ton of lights with LED switches and haven't seen one failure, including some of my regular used modded EDC's I've used for 2-3+ years. Think I had couple Q8 users who said it failed and the reset fixed it.

Of course it's possible you had Q8's from a batch with suspect parts or quality issues. If you are comfortable with it, I'd check the switch PCB first before ordering a replacement.

The first 500 Q8’s (or was it the first 150?) had quality issues with the switch leds. The later batches had better quality switch led boards. Many people with a failed switch received a new switch-board at the time. But I’m not surprised if switch leds from the first 500 that did work, fail at some later point. So it is good that Sofirn sells the improved board.

But it is also possible that in some cases people claiming failing switch leds in fact had switched them off without knowing.

+1 - forgot there were quality issues in the early batch... Thanx djozz! I'm forgetting more than I remember, or that I forget - I forget which

Yes, I had 3 of the first batch. One switch had bad leds on arrival and a second one failed more than 6 months later

Hey, if I buy BLF Q8 can I use my XTAR VC2S charger or I need to buy 4 slots charger? I’ll buy 4 new cells.

There’s no problem charging them in two batches. The parallel configuration in the Q8 does not require perfect charge matching.
It is always a good idea of course to keep the 4 cells together so that they receive the same wear over time.

The charge matching is one of the big reasons I like the SP36. Having a built-in charger allows me to charge all the cells at once, to exactly the same level… even if that level isn’t 4.20V. Otherwise it’s kind of hard to do a partial charge on a married set of cells.

But if you’re charging until full, there should be no problem charging two cells then charging the other two.

How many are considering adding the new 3v xhp50.2 on a LED4POWER mcpcb?

The Q8 seems like a great choice for this new led.

How many lumens would those give out in a Q8?

Not considering it, it is going to happen the day the leds come in (will take a while, they come via the CRX group buy). Lumens? About 12K

Wow that is a huge difference.

Can this diffuse survive on Q8 12K lumens?

https://www.aliexpress.com/store/product/2pcs-lot-White-diffuser-for-sofirn-C01-C01S-SP10-SF14-Q8/2933049_32991805908.html

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.