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Discussion Starter · #1 ·
Good afternoon gents. A while back I picked up some cheapos on amazon. Up until recently, they have worked flawlessly.. and for the money, I can't complain. One of the units quit working and I was wondering if you guys could point me toward some steps to troubleshooting the problem.

This is the type of light/battery in question:
http://www.amazon.com/DODOLIGHTNESS-Cycling-Bicycle-HeadLight-Headlamp/dp/B00OZ1J3TY

I believe the light unit itself is fine and this could merely be shitty batteries failing. The battery pack shows a green light when plugged in as if it was fully charged. Any help would be appreciated.
 

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RAKC
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Do the lights on the back of it light up when you plug battery in?

And though run time and such may be horrible, the pack will continue to work the light. If the light wont turn on with any battery plugged in, the driver in the light is either fried or broke.
 

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Discussion Starter · #3 ·
Thanks for the reply Tigris, I get no lights at all. It appears that the driver is toast. Is this something that can be fixed somewhat easily or should this be retired to the bin?
 

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Discussion Starter · #5 ·
I fixed two Magicshine lights for friends. In both cases I found broken connections on the driver PCB due to poor quality assembly. Easy fix if you have soldering capability.
Awesome. I'll crack it open later and take a look. Thanks for the tip!
 

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RAKC
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Like vanc said the "broke" part. I didn't think of it before but there is a copper coil around a ferrite donut and one of the ends that solders to the driver board seems to break (guys here pointed out to hot glue then coil to the driver board to avoid this issue). Since I have done that to any drivers that use the coils ive had no issues.
 

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Discussion Starter · #7 ·
I hope it's that simple. Its a great little light, especially for the money. I'll post an image once I open it up.
 

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Light freak
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Could be the battery

Could also be a dead cell or protection circuit died. I would measure your battery voltage first before tearing anything apart. Can you try a battery from another light or that battery on a light that you know works to rule out the battery?


****
 

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Discussion Starter · #9 ·
Could also be a dead cell or protection circuit died. I would measure your battery voltage first before tearing anything apart. Can you try a battery from another light or that battery on a light that you know works to rule out the battery?


****
I'll try to test the battery but I have no other lights that I could use for testing. They all use different connections for their respective batteries.
 

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RAKC
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Most of them are actually the same. If its a female om the battery and male on the light they should plug in. The threaded cap set up some use doesn't matter for testing purposes, it just adds a different form of waterproofing and securing the connection together
 

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Discussion Starter · #11 ·
Alright gents.. I opened up the light to take a peek at the PCB and check solders. I didn't notice anything abnormal except a small amount of discoloration around the white wire casing next to "IN-" on the left. All other connections seem to be fine. Sorry for the crappy iphone pic. IMG_2112.jpg
 

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Another pretty common failure point is a burned out current sense resistor. I've not worked on one of those particular drivers before so cannot point specifically to it. It will be a very low resistance value resistor in the circuit usually just before one of the wires that goes to the LEDs.
 
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