Burned magnetic driver

Hi,

I’ve got a flashlight for repair from my friend. He told me that flashlight has lost his power. I have opened it and i saw PCB with burned capacitor. I replaced the capacitor but nothing has changed. Flashlights takes 5mA on high and 2,5mA on low setting.
If anyone had a similar problem please help fixing the flashlight. The driver is HX-1424-B


Best Regards,
Damian

Well, to my knowledge, capacitors are quite resistant components, I think the only way that capacitor can die is to receive voltage higher than his rated V.
That would mean that one or more components that come before this capacitor also failed.
You can see extensive burn marks on the board, I would check if all traces are ok and all components that are just before and after that capacitor.
Maybe if you desolder the coil and post another macro photo of the components!

Best luck finding solution, drivers with magnetic control are not that common or easy to find…

I was goofing around with a similure magnetic 2 cell flashlight. well it ran fine with three. 4= I lost the mag control and only ran wide open 5= magic smoke.

So after you fix that one I have one more for you. :wink:

May have been a tantalum capacitor. They like to blow up, especially if cells are put in backwards.

Regarding your question OP. Can you clean the driver with alcohol or something and take a better picture with the toroidal inductor tilted up? One of the resistors looks like it might be burned out, but it's not clear.

I removed my SolarStorm Dx3 and take photo for you. Enjoy. :slight_smile:

How do i cancel a low-battery warning blinking?

You can’t, that’s programmed into MCU and reprogramming driver with magnet sensors is not easy.

Hmm… My problem is: “Flashlight voltage range: — 7.2v-8.4v —. 2× 4.2v(full charged) = 8.4v. Test flashlight runtime(high mode): 1 hour. Then low-battery warning blinking. I measure my batteries with voltmeter: 3.6v. So 2×3.6v = 7.2v. But batteries not yet %50 capacity. How can i fix this problem?

Thanks for your answer and sorry for my english… I hope you understand me.

What kind of batteries are you using? Might be that the batteries are poor quality and their voltage goes much lower under load.

My batteries: x4 Panasonic NCR18650B and x5 Panasonic NCR18650B Protected. I test this batteries and i got the same result.

I’m not personally familiar with the SolarStorm Dx3, but looking at the specs I see it can take 2x 26650 cells or 2x 18650. Driving 3 XMLs from only 2 cells is challenging for many lights… even NCR18650Bs will tend to sag a lot under such a high load, which is probably why you are getting the low battery warning prematurely. You might find using higher current 18650s or even better 26650s would help with this problem.

At 3.6 volts the batteries are nearly used up. with voltage sag when the light is running the voltage is probably dropping below 3 volts. Check out hkj's battery comparitor to check the voltage levels at different currents.

Looking at the new driver pic, no obvious issues noticed. Are you saying this is a different driver than the one with that doesn't work?

Without any other info, it seems that the QX9920 buck converter may have failed. Just a guess though. It is the chip label "LEDA 132x". They are very cheap. So getting some so you can swap out one in should not set you back much.

My batteries comparision:

I think my batteries not enough??

Does have a suggestion for the battery? Brand and model? Best runtime for my torch?

I did extensive research… And I buy 4x MXJO 26650 3500mAh battery. I’m waiting agog for test this batteries performance… I hope I’ve made the right choice…