U5 Cree L�D spotlight modification
 

Hi All.

I hope this is the correct or best place for this post.

I have bought a U5 cree LED spotlight from a Chinese website (Bang....)

http://i281.photobucket.com/albums/k...450/u5cree.jpg

I see from many other users on various forums that it has the annoying high, low, strobe effect associated with many Chinese Cree torches.

I (with a friend at work) have looked at the guts of one of these lights to spot what causes the three modes and how to "fix" it to one of them (not the strobe obviously).

It didnt take too long to spot the PWM controller and fix the light to a permanent high output. So no more low or strobe effects!

Its a simple fix and all you will need is an 0805 chip 10-12k resistor, soldering iron and (depending on how you work) thermal compound.

I wont cover the strip of the light. Its simple enough but if people want a full instruction sheet i will put one together.

Simply remove the PWM controller (U2) and solder the chip resistor to pin 1 and 3 (shown below).

Reassemble the lamp and Roberts your mothers brother.

Hope its of some help.

http://i281.photobucket.com/albums/kk208/HOG1450/U5.jpg

http://i281.photobucket.com/albums/k...450/U5_mod.jpg

Thanks for sharing this post. I've searched the internet for a very long time but never found any usefull info about removing the strobe function. And now I find it on my favorite forum.

But, unfortunately, the lightbrackets are of a very poor quality and after about 1000 km one of them decided it was time to take its own way and fell of the bike. So I replaced them with Shin-Yo lights.

I opened up my second lamp today to repeat the operation and found A) a plastic not glass lens and B) a different board!

Never fear. The component was still marked U2 and the same modification worked faultlessly.

http://i281.photobucket.com/albums/k...OG1450/u52.png

http://i281.photobucket.com/albums/k...OG1450/u53.png

Hmm...thought I'd found a solution to my identical problem when I found this thread, but no...seems they have changed the circuit board again. Mostly the same components but they have turned the U2 chip 90 degrees, either to the left or to the right...any clues?


http://i77.photobucket.com/albums/j5...t/IMG_5376.jpg

this guy is onto something but putting it through google translator didn't offer anything concrete
http://mazped.com/2015/11/08/bagaima...-pada-cree-u2/

Thanks!

Actually I think that link might be helpful...it's in indonesian, and it SEEMS that removing the whole U2 chip might do the trick, but he did not solder in any new components either...I'll keep you posted, I'll try to show it to someone who actually know something about electronics...:D

Modifying the lights has not been my top priority but yesterday I finally got to it.

Tried connecting current and connecting different legs on the U2 chip first. At best the high beam came on just about every time, but mainly soldering some of the legs together would only screw up the sequence.

Then I decided that I will never use the lights if they do not work only as high beam an pulled off the chip altogheter, and voila: only high beam left!

That's brilliant news, I can get on with getting mine sorted now.

Hi Guys

Just to back up what Matias has posted. I've just removed the u2 chip from the light and it works.

http://i64.photobucket.com/albums/h1...55576ECECF.jpg

Thanks everyone :040:

U5cree
 

yep, I did the same; just flicked the U2 chip off with a screwdriver and now have main beam only. Pretty good too....for �17.50!

Hi everyone first time poster (be gentle ha)
i'm trying to fix the annoying modes aswell but when i took the units apart i found no u2 chip and a board that looks entirely different from the ones above. Anyone have any ideas? TIA
https://attachment.outlook.office.ne...live.com&isc=1

I'd suggest you take out the two screws and remove the circuit board. It is quite possible that the U2 chip is soldered onto the other side of the board. You don't seem to have as many components on your circuit board as the others which leads me to believe some are on the other side?

good thinking, but no luck :(

Oh well, back to the drawing board then.

The only thing I can suggest that might help is that, being as there is no 8-pin chip in a 'U2' slot (the others seem to have 2x ICs, one in the 'U1' and one in the 'U2' slots) and it still has three modes, the only component on the circuit board in your picture that can be responsible for the mode switching is the 6-pin chip in the 'U1' slot as it is the only integrated circuit (coded U) there is. All the other components are resistors (coded R), capacitors (Cs), diodes (Ds), a transistor (Qs) and a power inductor (Ls). The big question is what you would need to do to that chip in order to disable the modes...?

Begs the slightly daft question... has it has actually got three modes?

Ha yes I checked and unfortunately it does have the 3 modes.
Ok that's a lot clearer now (sort of ha) I have have verrrry basic electrical knowledge y'see. But if I'm correct would it be worth it/safe to bridge some of the pins on the u1 chip and then if successful, as mentioned earlier in the post, solder the pins?

You could try bridging the pins and see what happens, however without knowing what the chip is, I wouldn't like to suggest where to start.

I can't see from the photo, but has the chip got any numbers, letters or markings on it?

Hi
I'm also trying to do this but does not work with my leds.
I discovered that shorting the c2 capacitor after power off the mode is reseted, looks like looses memory and starts with full beam, but with power it does not work, It cannot be shorted with power...
I made a continuous test with my multimeter and draw the picture:
(don't wory about the left side I'm not using that led)
https://lh3.googleusercontent.com/sl...y=w966-h920-no
https://goo.gl/photos/KQVkFg62RFNjJSdVA

Shorting the capacitor, as you've found, will dump the memory. Are you trying to short it temporarily with a fly lead, or have you tried permanently shorting it?

Anyhow, your circuit board is one of the easier ones to deal with. Just take out the chip in the U2 slot and it will revert to the high beam mode all the time. It would appear that you don't actually need to solder a resistor between pins 1 and 3 as in the OP.

This video shows what to do in a slightly ham-fisted way and it's quite amusing too as the chap sounds just like Cleveland from Family Guy!

On further reflection I think the culpit on your circuit board might be the transistor in the Q1 position. Your board looks remarkably simplar in terms of components as the board in the cree three-mode flashlight here. The fix in this case was to ground pin 1 of the transistor to enable full beam only. This maybe worth a try?

Removing the U2 does not do anything to the main led.
The permanent shorting of the capacitor does not work because the led wont turn on.
Also tried removing the Q5 and connecting it directly works but it is draining 4 times the normal amount of amps, and I don't know if it will burn the led of anything else so if nothing more works maybe it will be the thing to do.
I have a lab power supply and it tells me how much amps it is consumes:
At 6v
Max mode: 0,4a
Min mode: 0,2a
strobe: betwen 0,2 and 0,4

And if I conect it direcly it consumes 2A. isn't it a lot?

Thanks Pleiades really appreciate the help. I am working away from home for a week or two so will have a look when I get home, fingers crossed.

No worries. I'm interested in the solution (if you find one). Keep us posted with how you get on/what you find.

I think I found a way for led start always with full power.
I put a 10k ohm resistor on the cap that holds memory of the last mode, so after powering off the led, if I wait 3 seconds it discharges, if I plug power sooner it changes mode. Not perfect but is a workaround...
https://lh3.googleusercontent.com/5n...Q=w939-h920-no

I also have another led but when testing around I ended up destroying the U1 chip and the Q1 Transistor. Is there a way to connect directly or I need some chip?

Did you try cutting out the u2 chip? I think that was the one mentioned earlier in the thread?

Yes I did, But did not do anything, this u2 chip is for the blue and red led that I will not be using.

ooo the rascals, not sure why do they keep changing the design. that's the 4th variant on that board ive seen now.

So my attempts were unsuccessful :(
I tried to ground the pin and i must have accidentally shorted it somewhere else as well so when i applied the 12v feed i had a squeak, a pop and then a puff of smoke from one of the resistors. On the other light i decided to remove the u1 chip, now both lights oddly behave in the same way the leds light up at full brightness then dim down to i guess what would have been the dim mode. the strobe mode is gone so i guess 2 out of 3 isn't bad haha.

I think the moral of this tale is probably... Spend a few more pennies and get a pair of lights that only have one mode in the first place! ;)

We got one to work by removing the U2 chip, but when we ordered another one it had a totally different circuit board. It seems as though the U2 chip is missing on the new circuit board.

https://i.imgur.com/4bKfCwh.jpg
The picture shows the new U5 circuit board, which still uses 3 modes, on the left, and the working U5 which works and uses the full light mode only (you can see the U2 chip has been removed).

Does anybody have a fix for this? I haven't found a video yet with this exact version.