Hi, I have a flashlight and its batteries are dead. My friend and I put in new batteries, but it turned out that someone climbed into the circuit and replaced one transistor (he put bipolar, red cross paint), now the flashlight does not work, it turns on, detects the battery and goes into protection. The transistor itself is very hot, the only element on the board that heats up. I think I should put a field-effect transistor. It seems that his task is only to turn on and off the battery, like a key.
But I would like to ask for help, maybe someone has the same flashlight, will he disassemble it and take a picture of the transistor that is in the original?
All this is inside the body intended for charging. Model SF Beast II.
5 PCBs not counting the one with the indicator LED lol, that’s an HID flashlight right ? I didn’t know those needed that many components.
Anyway if it’s a low side NFET reverse polarity protection then it should be like this :
Check that the circuit matches with a to-220 (if that was the original package used ?) pin-out to confirm that it was indeed a reverse protection NFET originally.
Then choose one with low RdsON, a Vds and Vgs>=16V (needs to be more than 3x4.2V).
Or if you want to forgo the reverse protection then you can short the drain (bat-) and source traces (driver GND).
Thank you all so much for your help! I will try to change the transistor and tell you about the results.
Yes, this is HID 2006 - 1*D1S 4300K (2000 lm) + 12*5 mm LED (20 lm)
So the board is disconnected, where there are 2 pads with solder, a 15 amp fuse was installed. Maybe in place of this suspicious transistor should be the same as these 3 on the left?
My friend and I do not understand how everything works here, it seems that this missile control board
Surefire Beast II, catalog page 60-61, but this is not in the head of the flashlight itself, it is in its li-ion rechargeable body. The catalog shows only the battery body for 20 CR123
thats a teccor part.
all i recall them making are scr and triac.
neither of which have a place in this unit.
and the tab MUST! be soldered to the copper.
the board trace is the heatsink.
so look for a n channel with the lowest rdson and at least 40v.
should be easy.
same case as the 3 others.
maybe same part?