Nitefire NFT-90 9x XM-L Light - Need help with the driver

[GBD]

@Tom E

For your next mode memory problem, I see one cap on that driver board, and thinking it may be the cause. If you leave the light off for like 30 minutes, does it still come on in the next mode? How about over night? If not, then there’s probably a cap draining slowly over time, then once it’s drained, the light will reset and come back on in your first mode, not next mode. I’m no expert at this “next mode memory” fix’ing either, but guys have been saying that and I know with some light drivers like the Jacbo A60, it did work. I seem to recall you could power-up the light, power it down, ground out the cap by using a screwdriver or something to ground one end to the other end, then try powering up and see if it comes up in the 1st mode. If so, then you know the cap is the cause — to fix it, not sure best solution. Many times, you can use a resistor soldered across it Not sure offhand what value, or if it varies, what’s safest, etc….

Wish more driver guys would chime in….

If there’s a fix for the cap, then it’s possible to force the light to come up in the 1st mode every time, which is much better than next mode.

For the power, typically these lights stock would be driven like 1 to maybe 1.5A per emitter tops, so from there, guessing 3 to 4.5A, to maybe 5-5.5A with loss’s. From what you are describing, it’s sort of pointing to that your DMM has a lot of resistance, so reading artifically lower and able to run on high. With the tailcap on, you are getting even higher amps. This amount of amps sounds crazy for a stock light like this - haven’t heard of a direct drive “high # of LED’s” light, just haven’t seen it, and would be scary if it existed. Maybe there’s something wrong with your piece, or just a really poor, dangerous designed light. That driver does look awfully simple…. It’s scary to me….

The stock driver in one of my lights pulled 6.7A from fresh u.p.TFs, but died soon, the other would not pull more than 5.8A from same batteries. That is why I tried the 9A buck driver, to replace the dead one.

[Tom_E]

Wow GBD - sounds a bit scary. Inconsistencies, and dangerous ones at that. Chances are the light was not designed in it's stock form to run that high, so the driver dying isn't surprising.

[Tom_182]

haven’t heard of a direct drive “high # of LED’s” light, just haven’t seen it, and would be scary if it existed

Well here you are. This thing is sick. It´s possible that i could not meassure higher currents because of my DMM´s wires. More it more i understand why it is obviously designed for unprotected batteries. With protected batteries you can´t screw the tailcap on completely. Even shorter Flat-Tops don´t fit. So with unprotected cells i think this thing is a killer. The only thing is i´m a bit afraid of unprotected batteries. Especially three of them in series…. :~
Another thing is how long it will last….

For your next mode memory problem, I see one cap on that driver board, and thinking it may be the cause. If you leave the light off for like 30 minutes, does it still come on in the next mode? How about over night? If not, then there’s probably a cap draining slowly over time, then once it’s drained, the light will reset and come back on in your first mode, not next mode. I’m no expert at this “next mode memory” fix’ing either, but guys have been saying that and I know with some light drivers like the Jacbo A60, it did work. I seem to recall you could power-up the light, power it down, ground out the cap by using a screwdriver or something to ground one end to the other end, then try powering up and see if it comes up in the 1st mode. If so, then you know the cap is the cause — to fix it, not sure best solution. Many times, you can use a resistor soldered across it Not sure offhand what value, or if it varies, what’s safest, etc….

That sounds interesting but it doesn´t matter if i take out the batteries for a longer time or not. The light always turns on in the next mode… :Sp