[Solved] Flickering occur at high temperature.

Use solid copper wire as pillar. You can buy the 13A household internal wiring for like RM3 per meter. Make sure to get the solid cores and not the strands (normally ours will have 3 cores).

For the iron, the hobbyking one is about $7 shipped. Locally (other brand) much more expensive at about RM70 or so ($22).

I hadn't thought of the AC leakage issue, that could definitely cause some issues.

I do bend the legs, but there's a right way and a wrong way to do it. You really need to support the chip body well while you do it so that most of the stress is on the metal legs and not on the chip body. I use a pair of needle nose pliers that have a section with a nice 90 degree edge. I put the chip so that I can't see any of the body sticking out, indicating that it is well supported, then bend.

With your amount of flickering though I'd be leaning more towards the soldering iron than the 7135 chips, unless you're overheating everything badly.

when I read it I thought u where damaging those chipset by heat, but AC leak can damage too for sure, if u ground the driver during soldering. so yes that morse maybe is grounded?

Richard, can’t blame you for not thinking of the AC leakage issue, as who else is using a crappy $2 soldering iron like me? :stuck_out_tongue: Guess I have perfectly interpreted the meaning and spirit of *BUDGET*lightforum. :smiley:

Yes I did supported the body of the 7135 chip well when I bended their legs. I used two tweezers to do it, one tweezer to firmly press and grip the body of the chip, while exposing just the legs outside I used another tweezer to bend the legs.

About overheating, I don’t know how to measure but I guess it is unlikely. I used a lot of flux as emphasized by Tom E, so once my iron tip touched the legs of the chip there was buzzing sound and within 3 seconds the solder bridged both of the bottom and top leg together.

Agreed. It’s gotta be something with your soldering. Or maybe the switch.

Have you tried bypassing the switch? Remove the tailcap and connect fully power using a jumper or a screwdriver. Do you still get a flicker? Also make sure the tailcap spring is solder-braided.

Also, visually inspect your solder work on the 7135 chips under a magnifying glass.

Another thing to check is to make sure the star is secured to the pill and has thermal compound or adhesive underneath. I had a light I was working on recently that would flicker and then fail during testing. Turns out I wasn’t using enough thermal glue and it was separating from the pill. This then caused the solder around the leadwires to the star to melt breaking the connection. I fixed this problem by drilling holes and screwing the star down to the pill with a layer of AS5 between.

$2 soldering iron? ouch!

I use a 6 watt battery powered soldering iron for working on 7135s. Very fine tip and with the low power less likely to damage them I hope. I use a 40 watt for most other soldering.

Yeah I have eliminated the factor of switch and flashlight tube. You can refer to post #34 to see how I tested this stuff.

Yes I am using a $2 soldering iron as being a cheap skate lol. Seems like some of you guys are using those battery powered soldering iron, do you have any recommendation where can I buy them? The seller must be able to ship to my country and I don’t live in USA.

Does Hobbyking ship to Malaysia? That station is great for the money, around $15 plus shipping. I also started with a $6 budget iron, but fortunately it didn't leak AC like yours does. When you said earlier that you heard a "buzzing" sound while soldering the legs...I thought maybe it was just a language barrier/translation issue but if it really was a buzzing sound then yeah...that's not normal!

I no longer think your issue is with overheating, bad switch, etc. I think we've ruled that out.

I keep on planning to make a "close up" video of soldering 7135s...but I never seem to have the time. It's on my "to do" list for the summer. After soldering so many 7135s I can honestly almost do it without looking, it's like second nature now. It wasn't always like that though, I looked at the first couple of drivers I did last year for my own lights and while they don't look as nice, and they took me about ten times as long, they work just fine. So, you don't have to be a rocket scientist and they don't have to look pretty to work well, but it doesn't help when your equipment is sabotaging you (zapping your chips!)

Sorry, I mean bubbling effect when I touched the area filled with flux with my iron tip, and what I was trying to convey is the iron was definitely hot enough to make the solder melted fast without prolonged heating. It wasn’t electronics buzzing sound from the soldering iron. English is not my primary language and sometimes I was just too lazy to proofread my post. :frowning:

$15 is good to me, but I have to find out if they could ship here without ridiculous shipping charge. If the hobbyking warehouse is based in USA then there is a very high chance that they won’t ship to my country.

EDIT: Yeah I definitely would like to watch your tutorial video on some soldering tasks! Old Lumens have them uploaded before, but different guys may have different ways to get the same job done. I have modded quite a number of Qlite/Nanjg driver by stacking those 7135 chips so far but only few of them work fine and without flickers… but the similarities among them? I used $2 soldering iron to work with them. :smiley:

It’s $15 for the good hobbyking station + about $23 shipping to MY last time I checked. Total close to $40, quite prohibitive. That was why I picked two of the $3 portable iron with $6 shipping instead. Turned out I like them very much.

$40 is close to retail price of similar hakko clone here anyway, and no waiting required.

Yeah that is pretty expensive and exactly as what I thought. The shipping cost is even higher than the price of the iron itself. :frowning:

I am considering of this budget soldering station from DX, any thoughts about this?

And Pulsar13, how about this budget Hakko iron? Do you recommend it?


I bought the Yihua 936 soldering station from hobbyking to stack the 7135 chips. The results: Done modifying two new Qlite drivers and both of them STILL flicker! :frowning: This factor out the soldering iron problem.

I tried really hard to find out what could be the possible root-cause but still unable to figure out. Really hate to say this, but I think I should just stop messing with these Nanjg drivers as I have ruined about 10 of them so far, should stop spending money on buying new Qlite drivers, I am just too incompetent.

I remember yesterday I just said I will stop giving sh*t about modding these Qlite drivers, but it was the unbending attitude of mine that led me to do some more tests again. I hooked up a STOCK Qlite driver with the LED sitting on the pill with AS5 under the Noctigon, just exactly the same setup as in post #34 , as this way we can eliminate the factors of poor contact of the flashlight body, screwing parts, switch… and blah blah blah.



I know this doesn’t make much sense as I understand that these Qlite drivers have the exact same components as the other Nanjg type drivers, except that it uses 380mA chips and flashed with different firmware, BUT I really started to suspect about these Qlite drivers!

On the other hand Richard from Mountain Electronics has modded a bunch of the XinTD C8s (with Qlite driver) and has never have such issue as mine. Now I can’t explain this and let me call it a mystery. :cowboy_hat_face:

There's something else going on; there's no way that you got that many defective drivers. I have had a few duds, but to my recollection they just didn't work at all the or moonlight mode flickered or wouldn't work, but not the other modes. 5 in a row is a statistical improbability, 10+ in a row is pretty much a statistical impossibility.

I understand that you've got to be very frustrated right now. I feel for ya. I don't remember, but have you tried a different LED?

Thank you very much Richard for still being patience to reply in this thread. I can imagine that many people don’t bother my stupidity anymore and I can’t blame them lol.

You are right, that it is quite unlikely that I got so many defective Qlite drivers in a row, but I can’t find any other rationale of this phenomenon as of now. As for your information the soldering station I’m now using is the Yihua 936 from Hobbyking. It is not some high end stuff but at least it was reportedly good, isn’t it?

I did not test the drivers with another LED, but when I hooked my battery directly to the LED (direct drive) it doesn’t flicker at all, so I guess this way we can eliminate the LED factor?

And you know what, I just ordered 5 pieces of these Nanjg drivers from Fasttech this afternoon. As I said they are actually the same as the Qlite drivers but I just have an urge to give them another try. :frowning:

By the way I just done modding my Tangsfire HD2010 purchased from OL’s group buy a moment ago with my old $2 soldering iron simply because it does heat up and melt things much faster compared with my Yihua 936, at the same time I wish to experiment if my $2 soldering iron will do any damage to the East-092 driver. I use dedomed XM-L2 U2 1A on 16mm Noctigon, 22awg wires, copper-braiding the driver spring and tail cap spring and using the East-092 driver that came with it.


NO flickers occurred at all in all modes while drawing 4.50A on high.

Maybe this Tangsfire mod has nothing to do with the Qlite driver issue at all but just feel like to mention it here.

Just try with another LED (as I did in similar situation)

Yes. Try another emitter. The one you have might not be reflowed on perfectly and is causing the intermittent flickering. It can’t be all the drivers, so it’s something else. We must find it.
We must!

Thank you chiefinspectorfinch and Ouchyfoot, while I’m a bit tired of finding out why on this you guys just gave me some more motivations. :slight_smile:

Did you guys have any poorly reflowed LED that causes flickering before? And how could we explain that the LED doesn’t flicker when it was direct-driven?

Anyway I will take your advice and go home to try with another emitter/reflow again after work. :slight_smile:

That’s the BLF spirit!

I've had a bad LED before that flickered no matter what driver I paired it with. Didn't try it direct drive, though.