Okai, similar to my first topic
today I’ll share my second modding experience.
I’ll try to be more concise. Bear with me for my english, I’m italian and usually we don’t even know our mother tongue…so…
Ok, i ordered a Convoy C8 from GearBest,which ended to be a partially fake one (seem to be the only fake part was the driver which had an ugly crappy spring, tailcap switch seems ok)
Then I had 10 AMC7135 from fasttech bought almost only for the C8 driver.
So I measured tailcap current draw 2.6+ Amp, with a not fully charged 25R. Now that i had the basics starting numbers i started stacking 2 more 7135 chips
Measured again with my bench power supply 2.8A…hum maths doesn’t seem to be accurate, it should go well over 3A.
Oh, wait! Isn’t obvious, I’m capped by that crappy spring. I don’t have a better spring….ok, spring wire bypassed by copper braid.
I should not be saying that in any moment, with any minimal mod from adding a single 7135 to spring bypass i always did a check of the driver being functional, as I’m prone to destroy things because I’m clumsy as hell.
Everything worked.
I even bought a magnifier lens with leds to do things better, a STanley vice made just for electronics jobs…
Oh boy, I’m proud of me, that thing worked. It made 3.127A on my bench. I reassembled everything and worked, yeppeeeeeyyy!!!
Than while I was making a walk with my dog, I started thinking, “why just 3.127” maybe one 7135 chip stacked has a pin not very well soldered, hum…wait…. the wires…… the LED wires, how tiny are them?? 40AWG or similar…tiny as an hair…I should swap them!
SUre, but i only had a 14AWG turnigy wire, and some 18AWG.
I disassmbled the head, while unscrewing it something bad happened…the LED….that nice T6-4C led fell of the star….Nooooooooooooooo!!!
My creature!!! What happened !!!
Ok, don’t panic, I’ll reflow it!
Back again downstairs in the garage, after seeing some Old Lumens videos on how to reflow a led.
I fired my hot hair gun, and tried a lot to resolder that led onto its star….took a while…a lot to be honest…but eventually it happened….Oh…hopefully my nice tinted led is still alive…Checked…yes it is!!!
the dome is hot…hum, and it almost fell off just by touching it by my nail…and so i did! a perfect dedome. What a nice day. Things were getting even better!
Check the led functionality, 1 second at 4.414Amp (that’s were i left my current limit for my bench power supply 4.15V@4.414A) , ok worked good!
Next step…drill bigger holes to make the 18AWG pass thru the pill. Step accomplished.
Final step solder the wire to the Njang board…wires are a bit thick but should work….well ehrm…. no. Everything is wasted
The nice tinted and beautifully dedomed Led now is dead
The njang board is fully functional Strobe, sos, modes and all, BUT the max current is 0.22A, other steps are 0.11A and 0.006A.
Don’t know what the #[]# happened, i thought i burned some chips while soldering wires, or maybe shorted something, I’ve seen the LED- wire PAD shorted a pin of the circuit board, but looking at the schematics it’s correct to be that way
I touched with the “-” wire of the led the output pin of every single 7135 chip and found that the current that flows through their trace is 0.195A.
I cannot understand, where that value comes from if I measure 0.22 total draw
the NJANG schematics seem pretty easy, what the h€ck happened? Could someone explain? Is it repairable? or should I order and wait 2 months for some spare NJANG 16mm board?
My purpose is to pass the 4+ A barrier with a 16mm driver so I’m also looking for Alternatives (cheap). Please do not suggest RMM (I’d love to buy from him…but) as it’s not feasible for non-US customers.
ALso …my Courui D01 described in my “First mod, a DISASTER” is still destroyed, looking for a nice driver available outside the USA.
Any thought about case1 and case2?