Lumapower LM31: Dead low mode every other click?

I just got my LM31 from BatteryJunction today. I am extremely impressed with the appearance brightness and durability of the light, but on mine, the low mode only works ever OTHER cycle. On every other cycle, the low mode does not turn on, but clicking again goes into HIGH.

Are there two resistors that go into low and one is burned out or something? I suspect some sort of defect in the tailcap.

i had a similiar problem last time around when i run it with 14500 cell and it turn out to be the resistor got burned.
Ricky came to the rescue or you can change the resistor yourself.
Ask Ricky what type of resistor it use.

What is the best way of contacting him?

I'm having trouble with mine too, some time I had trouble turning on the light. tonight I found that if I squeeze the head it will turn on and vice versa when the light is on, a squeeze on the head will turn it off. I've PM Mattk, hopefully he can help.

Any tips on how I should go about opening up the tailcap to take a look inside? It's not intuitively obvious which side of it I should start disassembling on, what tools to use, etc.

Since the light is brand new if I were you I would contact BatteryJunction and ask for a replacement.

In any case to get to the switch you have to unscrew the tailcap and take it away. Inside the tailcap, around the spring, you will see a black plastic ring with two tiny holes in it. With the help of a pair of needle nose pliers or even a toothpick you unscrew the ring and take it out. Then you push slowly but firmly on the switch until it comes out of the tailcap.
When handling the switch be very careful with those twin golden springs: it appears it is very easy to break them.
BTW this is the same procedure for changing the rubber boot covering the switch.

Thanks for the advice, I'll look at the switch a bit more this weekend. Probably wouldn't make a difference even if I did open it, but I'm rather curious how the procedure works so I can put in that GITD cap. I've PM'ed MattK and am awaiting his reply...

I wonder though if Lumapower would be willing to send me a replacement tailcap? This light and I have... umm... emotionally bonded and I'd be sad if I had to part with it for a week :mecry:


Do I get inducted into the flashaholics society for that statement?

You can ask for a replacement switch only and keep your complete body including the tailcap.

BTW there is a post by MattK in the CPFMarketplace that recommends for this type of issues to send an email to his Customer Service rather than PM him. He says that at BJ email is monitored continuously by some people while his PMs might be seen much later.

Point taken, I'll e-mail his CS.

Talk about FAST CS! I've already gotten word that the replacement ship has been shipped out. Thanks to KiloVolt's pointers I got the retainer thing off (sheesh never occurred to me it twists off like a hard piece of plastic -- I thought it was rubber and was picking at it for a while).

Meanwhile, I stuck the GITD cover on. Interestingly both the included black and GITD covers are flatter than the orange one, now allowing the light to stand up on its own. On the slight downside the button takes a bit more thumb-strain to push now, but I value the added candle mode

Was this light's name changed from LM301 to LM31? If so, was anything other than the name changed? Batteryjunction lists it as LM31 but the literature that shows up once you select the light still refers to it as LM301.

pilou said:

Was this light's name changed from LM301 to LM31? If so, was anything other than the name changed? Batteryjunction lists it as LM31 but the literature that shows up once you select the light still refers to it as LM301.

Click to expand...

Yes, the "new" SSC P4 version of the light is now called LM31 to distinguish it from the last-generation 301's. Apparently some first-shipment new ones said LM31 on the box but LM301 on the barrel too but that was corrected soon after.

http://www.lightreviews.info/lp_lm31/review.html
http://www.lightreviews.info/lp_lm301/review.html

Here's lightreview reviews of both for comparison. The SSC one labeled LM31 is clearly brighter. Also the new "low" mode seems to last for bloody forever!

at least yours worked some of the time. i just got an lm33 that was DOA

I wonder what is the failure rate of these lights? I want to buy these things for others as gifts, but these stories don't inspire confidence. Yes, I am confident that BatteryJunction's CS will get it right for me/them eventually but as a gift you expect it to work out of the box.

You could ask the people at BJ to briefly test the lights before shipping them. In actual facts being these LM simple straightforward lights it is enough to check that both levels work.

just to update, my light works perfect now.

i loosened the led assembly about 1/8th of a turn. it appears it was too tight from the factory and for whatever reason it wouldn't turn on?

good for you

ikelo said:

just to update, my light works perfect now.

i loosened the led assembly about 1/8th of a turn. it appears it was too tight from the factory and for whatever reason it wouldn't turn on?

Click to expand...

Congratulations. I've noticed that happening once with my LM31 when I mess with the head assembly too much -- at some twist locations it won't respond, but usually unscrewing/rescrewing it fixes the problem. Perhaps there's some shavings or excessively anodized bits in there.

I just went through one rundown of an NIMH cell and now switched to an alkaline. With the NiMH, the discharge curve is exactly as advertised: flat output, then rapid drop to a moon mode (within 2 minutes the bright mode had become a dim mode). More impressively, my Inova X1 semiregulated had already refused to light up on this NIMH cell so I assumed it dead from day 1, but the LM31 was able to suck another 45 minutes worth of HIGH output from it.

I'm impressed and can't wait for the replacement switch to arrive.

Got my replacement switch today, and immediately put it in. It's working great! I love this light, and BatteryJunction/Lumapower too!

Excellent !!

:twothumbs