I have a bad Convoy S2+. It works very inconsistently. It kinda blinks off then on randomly, making me think the driver is bad. It’s a SST40 w/ a 12-mode driver firmware. I have two questions.
I got the driver and LED assembly out of the light after watching some videos. But I can’t figure out how to disassemble the PCB from the light assembly. I see two circular openings on diametric sides of the brass ring that is covering the PCB. What tools might be useful to unscrew that? I tried needle nose pliers but no luck.
What can I replace the driver with? I’m comfortable with soldering wires to pads, but not with anything that requires fancy surface mount soldering. So looking for advice with something that is within my ability to install. Other considerations:
My intention is to use this for a bike light, as it’s my only light that has much throw.
Something in the 5000k range tint would be alright. I’m OK with the existing LED.
The Convoy S2+ uses a half-press to change modes, not sure how that factors into driver selection. Would like double-half-press for turbo.
I’m not worried about moonlight in this case (I got plenty other low moonlight lights). I would like regulated output on medium and medium-high so that light doesn’t dim progressively.
I don’t care too much if Turbo mode is timed vs. temperature controlled. Probably only use Turbo in emergencies.
LVP - disable the light before I damage the battery due to deep discharge.
Some kind of low-voltage warning would be nice. Maybe blink the main emitter twice or something like that? My other lights have aux LEDs on the button for low voltage indication.
I’m new to flashlight mods, so any additional advice would be welcomed.
To remove the driver you need to loosen the retaining ring. Use a pair of snap ring pliers (tweezers will work in a pinch but may bend) inserted into the two holes, not the notches, and unscrew.
That depends on what driver it uses, versions with more than 4*7135 do not come with a retainer ring, instead they are soldered on the pill with 2 solder blobs
Have you tried tightening the tailswitch retaining ring? Drivers themselves rarely go bad, so I would suspect a electrical contact issue might be causing your inconsistent behavior. To turn those restaining rings with the two holes I use a pair of thick crappy tweezers that I don’t care about bending some.
Your current 12 mode group driver satisfies most of your requirements. It does not have LVP I think, but LVP is not as necessary on this type of driver because it is very unlikely that you will damage your cell from overdischarge in this light. The voltage of the LED is such that when the cell is empty it draws very very little current. So your light will just become dim when the battery is low.
I recall there being some production issues with your driver that caused the electrical ground ring to be covered by a film that prevented good contact, so that is something you should check for when you take off the driver retaining ring. You can just scratch off the film, if it’s there, to fix the issue.
Snap-ring pliers OR needle nose pliers. In either case you may need to further file or grind down the tips to go fully into the hole to reach the bottom for full engagement.Then put some electrical tape on the threads before you wreck them in anyway.
I’m pretty sure that the 12-group version should have LVP. It’s very unlikely that they would forget to add LVP to the 12-group version when it’s a clone of Biscotti (the open source firmware used in the 7135 version) which has LVP, and uses the same hardware as the 4 modes version, which has LVP according to all reviews. IMHO you should contact Simon at Convoy, he can send you a replacement driver.
Before trashing anything, undo the retaining ring, jiggle everything around, then snug it up tight.
Same for the switch.
Better to take IPA or other cleaning solvent and and clean all the threads, contact points on the driver, everything.
Whenever stuff goes mental like that, odds are it’s something loose, even if it looks (and is) tight. Loose, dirty contact, anything that can make an iffy connection.
Then if everything’s still hosed, you got nothing to lose and can go swapping drivers or whatnot.
What Lightbringer said. Open everything, clean the threads, use some — just a little! — conductive lube like the conductive variety of Nyogel or “bulb grease” from an auto parts store.
Wipe the threrads and contact points with that stuff.
It’s very common for flickering or ghost button clicks to happen because of dirty contacts.
Oh and look at the ends of the springs. Often coil springs have just been snipped off with metal cutters leaving a sharp point that digs into the end of a battery at a tiny contact area, maybe putting a gouge in the negative end of the cell, and that small conact area can get dirty and intermittent. If you find that problem, bend the end of the spring slightly so it’s parallel with the end of the battery, smooth off any rough points —- to greatly increase the area of contact between the spring and the cell.
And add a dab of confuctive lube there also.
Many failings can be ascribed to intermittent contacts not driver failure.
Remember: the retaining ring in the pill has a (regular clockwise) righthand thread, while the retaining ring on the switch of an S2+ has a (counter clockwise) lefthand thread.
And take a closer look at the retaining ring of the switch. There should be NO visible gap between the switch-PCB and the ring. The PCB must snug fit IN a groove in the retaining ring.
Now that I’m dealing with this buggy light and seeing how many things can go wrong, I’m surprised I haven’t run into something with the other 3 lights I’ve gotten recently.
