Need help with a dead LSL

I have a problem with my LSL, I just swapped the LED from LD to HD about two days ago. It was working fine after assembly; but just last night after switching battery packs it no longer works, can a "cold" solder joint on LED damage the board?

The led still works but not the boost circuit.

Any idea on how much to repair it? Is it worth the trouble? Should I just sell it?

that may kill the 1618.but i have replaced a few smashed leds in the arc-ls that did no other damage.did you try to run the board outside the head?
look over the work you did for bad solder joints and loose solder balls.
if you give up i can always use another fixer upper or can do the repair for you.

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snakebite said:
...did you try to run the board outside the head?

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I did this before I reassembled it but now I get no response at all. /ubbthreads/images/graemlins/frown.gif /ubbthreads/images/graemlins/mad.gif

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snakebite said:
...look over the work you did for bad solder joints...

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I redid the LED contacts and no extra solder elsewhere.

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snakebite said:
...if you give up I can always use another fixer upper or can do the repair for you.

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Can you PM me a quote.

Ratus,

Just guessing here, maybe there's something wrong with the clicke or maybe the very small 33pF cap right beside the LT1618 got crushed when you screw in the retaining ring too tight. It would be nice if you take a picture of the board so we all can take a look and try to help.

scan it with a flatbed scanner and post the image.

How about this?

If you are willing to go along li-ion cell such as bare R123 or JSB123, a simple mod can be done to bring 450mA constant current for 1 hour run time.

Here is the modded LSL after too many times experimental abuse finally killed the board. The mod can be done by me or cgpeanut.

BTW, the large chip at the left is a micro-P to provide multiple brightness. Mod can be done without it if multi brightness, strobe and SOS are not wanted.



-- dj

DJ,
How do you control the multiple brightness?

DJ, coool board mod

Yep CY,It is cool.I have a ls board that has a very dim led.Part of the inductor housing is missing.It got messed up when I was installing a so17.I don't know if the led is bad or inductor or what.This mod of DJ's and cgpeanuts may bring it back to life.I would realy like to know more about it.

good scan.
i dont see anything that would cause your problem.
you have some sort of component failure .look where the flex pcb is folded for cracks in traces.


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Ratus said:
How about this?


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W4DIZ said:
DJ,
How do you control the multiple brightness?

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A simple PWM to on/off the LDO output. A little bit of intelligence in the PICdetermines which brightness or feature mode to switch on -- depending how many times you click or twist when you turn on.

As you can see from the picture, the board is very badly battered during many tests and eventually the LT1618 died and the threads on the board got cracked on many points.

The only way to revive was going with li-ion.

-- dj

Ratus,

EDIT:
Did you notice a cut trace on the 33nF cap on the left side of the LT1618 chip it's the smallest component on the arc-pcb looks like a cut trace, try re-soldering it to the pcb board that might be your problem providing there is no componet failure elsewhere.

Try re-soldering the diode maybe it has a bad solder joint. If that does not work, there is a component failure somewhere or like snakebite said, look for cracked traces expecially in the bottom board where the positive connects to the top part of the board while your'e at it might as well check the solder joint of the positive gold button re-solder if necessary.

I have a quicktime movie of the POPL on a prototype smd board in action can someone please inform me how to post a quicktime movie in CPF?

Here's a pic of it.



It's based on Doug_S's LDO and of course our resident PIC guru DJ How are you DJ?

I'm using TPS73601 for 800mA, IRLLM6401 for reverse polarity protection, .1uF cap which retains the last output level and of course the PIC12F675 4 components total 5 including the lux.

I've been busy modding some dead arc-ls board with pic using ti's TPS73201 for 400mA and TPS73601 for 800mA, I think 400mA is good balance between runtimen brightness and heat dissapation.

The only difference with DJ's awesome POPL-LDO-ARC-LS pcb mod is the addition of IRLLM6401 for reverse polarity protection.

Now the 800mA version might be placed in a M@G-4D it should provide more than enough metal to cool down the lux and as Doug_S said:

The TPS LDO part should have more copper associated with the ground pin for adequate heat dissapation. Without it, the TPS part may thermally shutdown with fully charged cell and/or low Vf Lux.

The battery charger is also based on DJ's LT4054 and was posted elsewhere.

The POPL will have 20%-40%-100% brightness When you switch on, it'll start with 20% brightness, switch off within 1 second and switch on, you get 40% brightness, switch off within 1 second and switch on, you get 100% brightness, then it cycles through to 20% again.

Roberto,
Can this above mod be used with a 123,or is this for r bats only?You have a PM.
DJ,Thank you for the info.

W4DIZ,

The POPL-LDO was primarily designed for li-on rechargeables. IMHO, CR123 cannot provide enough current flow to the luxeon led it will light up, but dimly. So NO on the CR123's

Now, Out of curiosity I used a dorcy 1-aa circuit to boost battery voltage from a single AA alkaline. It works and provides a decent light with multiple brightness which make me think hmm, another mod host for the POPL? /ubbthreads/images/graemlins/smile.gif

No cut traces that I can find, I checked the led connection its good.

Thanks for all the help, I just don't have enough experience to know what's wrong.

I think I'll sell this one and get something that can mod without a EE degree./ubbthreads/images/graemlins/icon23.gif

Ratus,
Maybe you could contact one of the guy's on Peters list that have offered to repair the Ls.It would be a shame not to have it working.

cgpeanut,Thanks for the info and keep up the great work.