Problem with two Quark flashlights - weird operation

I got two Quark flashlights recently from one European web shop. One QB2A and one QTA.

What I like:
1. Both are XP-G2 LEDs, which I like a lot more than XM-L2. Pure white, no green tint.
2. And also good throw because of the deep smooth reflector. Different than Zebralight design. Combined with 1, great for outdoor use
3. Good design and good finish

But with one big problem so far:
the turn on operation is not always bringing the light on the desired level!

1. If the flashlight is left there for some time without operation, then turn-on will bring the light to the level you programmed, but it will go to the brightest level first and then drop to the pre-defined level.

2. If I turn it off and then on, the light will go to the pre-defined level directly this time

3. If I turn it off and then on for a few times, then light will refuse to turn on anymore or will turn on to some very very low level.

4. If I turn off the light and leave it there without any operation for some long time, maybe more than 10 minutes (I did not try to find the exact time limits), then the light will perform starting from the first step over again!!!

The two lights are performing in this bad and weird way almost the same.

Are these two lights broken in the software part? What can I do? I really like these two lights when they are on, great beam. But the operation is really horrible and weird, even it is kind of predictable.

Four sevens has a 10 year warranty. I would recommend giving them a call. Odd that both lights are responding the same way...

1, 2 and 4 are typical Quark Tactical pre-flash behavior - it's normal. Quite common on XPG models, yet rare on XML models (in my experience). If you turn on a low mode, after using a high mode, or after the light has been sitting for a while, it will produce a full output pre-flash for a millisecond. I'm not an expert, but a member that built/sold flashlights and modded Quarks here once said it had to do with 47s use of a large capacitor, which improved reliability. No fix for it, you just have get used to blinking for first turn-on .

3 sounds to me like you may be inadvertently entering programming mode by squeezing the head/body when turning on/off while the head is close to the loose/tight bezel line. Tightening the head fully, or loosening the head a full half turn should stop this behavior. FWIW, on the Pro models, I use this slight thread play trick as a momentary-Max-from-ON "feature" and it's good enough to signal Morse code .

reppans said:

1, 2 and 4 are typical Quark Tactical pre-flash behavior - it's normal. Quite common on XPG models, yet rare on XML models (in my experience). If you turn on a low mode, after using a high mode, or after the light has been sitting for a while, it will produce a full output pre-flash for a millisecond. I'm not an expert, but a member that built/sold flashlights and modded Quarks here once said it had to do with 47s use of a large capacitor, which improved reliability. No fix for it, you just have get used to blinking for first turn-on .

3 sounds to me like you may be inadvertently entering programming mode by squeezing the head/body when turning on/off while the head is close to the loose/tight bezel line. Tightening the head fully, or loosening the head a full half turn should stop this behavior. FWIW, on the Pro models, I use this slight thread play trick as a momentary-Max-from-ON "feature" and it's good enough to signal Morse code .

Click to expand...

+1

I have a QT2A, and that sounds like normal behaviour if you don't know how to properly use/program the light. (Except for pre-flash, which unfortunately is common on the Quarks, but shouldn't be too annoying for most people.)

reppans said:

1, 2 and 4 are typical Quark Tactical pre-flash behavior - it's normal. Quite common on XPG models, yet rare on XML models (in my experience). If you turn on a low mode, after using a high mode, or after the light has been sitting for a while, it will produce a full output pre-flash for a millisecond. I'm not an expert, but a member that built/sold flashlights and modded Quarks here once said it had to do with 47s use of a large capacitor, which improved reliability. No fix for it, you just have get used to blinking for first turn-on .

3 sounds to me like you may be inadvertently entering programming mode by squeezing the head/body when turning on/off while the head is close to the loose/tight bezel line. Tightening the head fully, or loosening the head a full half turn should stop this behavior. FWIW, on the Pro models, I use this slight thread play trick as a momentary-Max-from-ON "feature" and it's good enough to signal Morse code .

Click to expand...

Thanks a lot! Especially the confirmation with the pre-flash point.

I also suspected that 3 is kind of related to the programming. But I did pay attention to put the head in the fully tight position. I will try more to see if there is some improvement.

WalkIntoTheLight said:

+1

I have a QT2A, and that sounds like normal behaviour if you don't know how to properly use/program the light. (Except for pre-flash, which unfortunately is common on the Quarks, but shouldn't be too annoying for most people.)

Click to expand...

Thanks too.

I will try more with programming to see if there is some improvement or coming back to normal.