That’s the low voltage warning. The cause of that if the battery is full would be high electrical resistance (poor contact) somewhere.
In addition to the retainer ring, check that the battery tube is not backwards. The “S2+” text should be towards the tail. It will physically fit if put backwards but contact will be rather poor. It’s also possible that the tail switch is defective.
This suggestion is definitely a first step in finding the cause. It helps to pinpoint the trouble to the head-section or to the tail-section. FWIW, this light occasionally has troubles if the switchboard is a fraction to large, it does not properly “sink in” the retaining ring of the tailcap assembly. Giving the retaining ring an extra nudge might help.
Please elaborate on the properties of the light. Is it a light with a rubber tailcap or a metal tailcap. Also specify the capacity of the driver. If it is an AMC7135*6 or AMC7135*8 driver, it is soldered to the pill. So no need for tightening a retaining ring on that end. Because there is none.
Brain fart on my end, forgot about the different chip quantities. :person_facepalming:
Great suggestions - thanks guys! I will check this tonight and report back.
Henk4U2, it has a metal tail cap and switch, not the rubber/silicone covered one. It has 8x 7135 chips. I’ll check the tail cap retaining ring per toddcshoe’s suggestion tonight, as well as jumpering the battery’s end directly to the body of the flashlight. The tail cap switch itself seems to function fine, at least based on feel, which probably isn’t saying much, but we’ll see.
Well, it isn’t the tail cap or switch. I jumpered the negative end of the battery to the body of the torch and got the same result - blinking light.
How do I remove the driver from the head? needle nose pliers? Driver Pic
Unscrew the head. You’ll see the pill in there, use the needlenose pliers to screw it off. I’m guessing the driver is soldered to the pill instead of held with a retaining ring - if it is you’ll have to de-solder it with an iron, otherwise use the pliers to unscrew the retaining ring.
Okay, I removed the pill with needle nose pliers - now what…
The only thing visually apparent is that the LED board separated from the pill slightly. There’s thermal transfer compound between the LED board and the pill surface, but they weren’t touching. The board is just floating a little above the pill. Is that an issue? I assume not as it must compress together once it’s pressed against the reflector in the body.
Is it worth de-soldering everything at this point and re-soldering the four connection points? I’ll be honest - I have very little soldering experience and my iron is a piece of junk. Perhaps it’s time to invest in a new one.
Battery fine. Contact Gearbest.
I’ve had 2 faulty items from them over the yrs (torches)
Under $20AUD.
Coupla Photo’s. Instant changeover. No quibbling.
Don’t bother returning old.
They’ve already refunded my money - I was just wondering if it’s worth trying to resurrect.
It is if you get a driver from Simon at Convoy’s Ali store. You can purchase Biscotti drivers at whatever number of 7135s you want at a very good price. The S2+’s host is practically a legend, and worth experimenting with.
Also yeah, it’s a good idea to get a better iron. My brother and I struggled quite a bit with a weak one that didn’t even melt the solder right, so I went ahead and got a decent 60w one in my following trip to the hardware store. All is good in the neighborhood for future driver or emitter swaps.
Yep. Always get Convoy lights directly from the manufacturer:
https://www.aliexpress.com/store/product/Gray-Convoy-S2-with-luminus-SST20-Ra-95-4000K-DTP-copper-plate-ar-coated-glass-lens/330416_32969287656.html
Here’s the soldering iron I use:
It works very well.
Thanks for all of the help, guys.
I went ahead and ordered a 7135 x8 driver w/ Biscotti firmware to replace the one that is presumably faulty in the S2+ I purchased from Gearbest.
and a Convoy S2+ with the SST-20 4000k emitter and 7135 x4 driver with Biscotti firmware.
Beautiful. I got that exact driver to replace the 3/5 I had on my first S2 – I have another one with 7135x6 Biscotti but this one has sentimental value (and the LED tint is rosier and nicer) –, and since I did the swap I’ve been enjoying it a lot. It’s been my go-to biking light in these final days of Daylight Savings Time when it’s complete darkness before 6AM (I leave the house between 5:30 and 5:45AM, when there’s barely a hint of dawn in the sky).
Just be careful not to run it pell mell at 100% power too long, the S2+ doesn’t have the cooling potential to safely maintain that much output. I like to keep my S2 at mode group 8 (max mode 50% of full power) and will do the same when my Nichia S2+ gets to me.
Yeah, I’ll probably leave it on mode 8 as well. How do you find the 7145 x6? Are you able to leave it at 100% for any longer?
When on 50% power with the 7135 x8 can you run it continuously?
Cheers!
It depends. I had a 7145 x6 turn on in my jacket by accident and it was too hot to hold after it was on for guessing 5 to 10 minutes. I had to hold it with my jacket sleeve just to be able to turn it to off. But holding it in my hand on other occasions, it was hot but bearable to hold.
I see, so it depends whether or not it’s connected to the human heat sink. 
cool.
I’d gone for it for heating reasons, but once I found a temperature test that indicated an S2+ in x6 reaching the same risky max temperature as x8 but a bit slower, I decided “bugger it” and went for x8 when I got the new drivers. I did notice the x8 being marginally brighter than the x6 on 10% mode and above.
On 50% it’s like you’re running a 7135x4 at full blast, which is very much tried and safe. During my 15-ish minute morning commute, it doesn’t even get warm. And the battery lasts forever. Not bad at all for swapping about 25% perceived brightness for more or less 2 more hours of runtime :laughing:
I ordered from AliExpress the same above ^
(2)S2+ 7135x8 And
(1)S2+ 7135x3
Two weeks ago and found out they’re on Chinese New Year vacation for a month. I think they’ll be back the 12th February
Nice. I’m looking forward to a high quality 4000 kelvin light. The SST-20 also looks to be efficient, with a higher lumen output than the 219C, I think.
