MTE "P7-D" SSC P7-C just received, have questions

Hi everyone,
I'm new to this forum and just purchased my first LED flashlight. I received this flashlight (MTE "P7-D" SSC P7-C 900 Lumen 5-mode http://www.dealextreme.com/details.dx/sku.16092) a few days ago and was somewhat disappointed in the performance of this flashlight. I have seen other peoples LED flashlights (surefires, husky, cheaper ones, etc) and this one does not seem any better. I think there may be something wrong with my flashlight. It flickers quite a bit in every mode and does not get hot at all. I left it on high mode for about 30 minutes and the whole flashlight was cold to the touch, not hot at all. I measured the volts of the batteries and they were 4.12v charged and then measured the wire leads next to the led bulb and it read 3.68v when in high mode.

My questions are, what can I do to make sure there is not something wrong with the flashlight. Should I measure the ohms on high mode and how would I go about doing so? Am I expecting too much from this flashlight? I don't really have anything to compare it to except for a 3 "C" battery incandescent Maglight.

I read a few threads saying to upgrade the wiring and bypass the resistors but I want to make sure there is nothing wrong with it first before I mod it and then try sending it back for replacement.

Also, if anyone else has this flashlight, can you post pics any pics of the led boards and light comparisons, etc..

Thanks for any help.

BTW,
Here are some pics of my setup:

I made my own 2D Mag with a P7 and drove it at spec to get 900 lumens and it blows away even my Surefire E2D-L. It should be far brighter than your 3D mag incandesant and when measureing voltage at the LED pins on high, you should be able to see.

I've got two of that same light, something sounds wrong. Its certainly not the 900 lumens claim, but its certainly above 500, it shames my two Q5 lights in output (but not throw). Mine get very warm if I run them for any length of time in a normal room without wind to cool them. I suspect your switch could be bad since you mention flickering as well. If you want, try bypassing the switch by using a thick paper clip to connect the bottom of the battery to the bare metal that the tail cap connects to (without tail cap installed).

The only flicker I notice on mine is almost imperceptible and occurs about 2 seconds after mode changes, it may have something to do with the memory feature since thats about how long it takes for a mode to be remembered.

I tried bypassing the tail cap switch and it still flickers the same amount. It flickers in every mode pretty bad. It flickers maybe like every 5-10 seconds randomly. I also took the whole LED unit out of the casing last night and unscrewed the screws from the top to try and see underneath the bulb and the circuit board but it would not separate and I didn't want to force anything.

Can someone please explain to me how to take apart the LED assembly so that I can see the back side of the board where the wires run down to? Also, what is the correct way to measure the amps while the light is on?

Thanks again.

ok i did some more reading and figured out how to measure the amps. I found out that there is only 0.18 amps current on high mode.

Is there anything I can do to try and fix this or should I just send it back to DX and try to get a new one?

I had a light with a similar design to that, but it was Q5, 2x18650. It was dead within 5 hours; there was an appalling thermal path to the body of the light, so the emitter just fried itself.

Run it on max for a few minutes, then unscrew the head and poke the pill the LED is on; try to see where heat is getting to, and where it isn't getting to. It might be that there's no thermal pathway between the emitter and the pill, or pill and flashlight body.

would that cause it to only run at 0.18 amps though?

I ran it for a few minutes and then took the reflector head off and touched around the led bulb and nothing was hot.

I have two MTE lights, a 5 mode 26 mm head and a 5 Mode 52 mm head. Both are expceptional, the larger is nearly as bright at my D bin, mod that runs at @ 900 lumens at 3.75 volts. I have other D bin and C bin mods all at 800 lumens + and the MTE lights are right in there.
Something is wrong with yours, sorry for the disappointment, you should blow away eveything else if they work correctly.

kcmfg said:

would that cause it to only run at 0.18 amps though?

I ran it for a few minutes and then took the reflector head off and touched around the led bulb and nothing was hot.

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Sorry, missed your post first time round. You should be getting ~2.8A, 0.18 means that something is seriously wrong, and it doesn't surprise me that everything's still cold at that drive level.

The light either has high resistance, the battery is bad, the LED has a high Vf or maybe a combination.

Not sure how you would fix it though.

I just filled out a return form with DX. I hope they exchange it for me. I think I know why it's so dim too, I noticed that only 1 of the 4 emitters are lighting. There is also something else wrong causing the flickering. Figures my first nice led I buy is defective.

kcmfg said:

I just filled out a return form with DX. I hope they exchange it for me. I think I know why it's so dim too, I noticed that only 1 of the 4 emitters are lighting. There is also something else wrong causing the flickering. Figures my first nice led I buy is defective.

Click to expand...

If you want a cheap reliable (and modable) P7 flashlight buy the trusfire with 2*18650 cells and if you want you can easily do this mod to add modes and drive it at full power.
You could possibly ask DX to exchange the 1 Lion to a 2*Lions version --> much better solution IMHO

JP

freedom2000 said:

If you want a cheap reliable (and modable) P7 flashlight buy the trusfire with 2*18650 cells and if you want you can easily do this mod to add modes and drive it at full power.
You could possibly ask DX to exchange the 1 Lion to a 2*Lions version --> much better solution IMHO

JP

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I don't think getting the current to flow higher would even help since only one out of the four emitters are lighting. You can see in this pic that only the bottom right one is lighting up. The P7 is just four P4 emitters in one is what I read.

that doesn't even look like the die that is lightning up is lighting up properly.. IMO that's probably a duff LED.

Jarl said:

that doesn't even look like the die that is lightning up is lighting up properly.. IMO that's probably a duff LED.

Click to expand...

Oups... It seems to me that the led is almost dead....

JP