After a long time I have dared to try to make some modification of my flashlights. I wanted to promote a Convoy 7135 C8 adding some chips. My soldering iron is 40W and is not very good but after much patience and after finding a way to make it easier to add four extra 7135 (Thank you Old-Lumens ! A video on soldering 7135 chips to a NANJG driver ). The problem I have is that once mounted flashlight just turn on “high”. I suspect I may have damaged the heat of any component or soldering with tin has joined two runways of the circuit by mistake. If anyone has ever had the same problem or imagine where the fault may be I would be very grateful to tell me I should check. Some photos if you can help (sorry for the quality, I’m bad with the photography)
SOLVED: the positive LED lead is touching the ground ring
Your positive LED lead is touching the ground ring. I don't know how it even works.
Did you know you don't need to solder the middle leg of 7135's? It's the ground. Same as the rear leg that touches the ground ring. Good job though. I hate stacking 7135's, which is why I'm so excited to finally start working with BLF's DD drivers...just waiting for them to arrive.
I suspect that the positive LED wasn’t shorted at the time he tested it. It wouldn’t have worked otherwise.
Heat can damage components. You did a good job at soldering, but maybe you didn’t wait between each solder for the board to cool down?
Maybe that you could check the voltage on the PWM pin. Do you have an oscilloscope?
That would tell you if the main IC is fried.
Checking for continuity between each pin is also a good start.
You guessed it perfectly!!! I tried to check the contacts of the chips 7135and I did not see the positive touching the ground ring… very thank you!
@leaftye: Yeah … looking for when I was impossible to weld the fourth chip 7135 I read in another post on the forum … and I realized when I saw the bottom of the 7135 :_(
@lagman: Honestly I did not expect much to components between soldering and welding to cool …… had a welder with 8w guess this would work much better but I have damaged. Next time I will do if your advice
I fix this bug again and resolder a chip that 7135 was not very good soldier. I changed cables by silicon 22awg and test with trustfire 2400mAh and this is the result I got:
3.53A on high
The new step will change the base led by a copper base :bigsmile:
the mark of the photo was not the fault, I check with the multimeter to see if it was in contact but no contact between 7135 and I clean a little tin that had a lot in that leg.
And I also cant wait to start trying some BLF driver of the Oshpark Projects, the problem is that I am from overseas and can not buy in digikey for example … later I have to do an order mtnelectronics, now sells the components needed to assemble
I added 7135 chips to convoy v2 driver… All modes of all groups working well but on every high mode of any group, it becomes low automatically and buzzing sound comes from driver… Even it is not getting hot…. Did you know about this problem
