# Third faulty Zebralight H501W



## Foxx510 (Jul 24, 2009)

I think I was never meant to have H501W lol. I got my second replacement light a few days ago, and it has the same fault as my second replacement, a different fault to the first faulty one I got. 

This fault is a strange one, as with the last replacement it will randomly start up in a "not quite HIGH" mode which pulls around 440mA. I just did some testing on a lab power supply and there is no consistency to the fault, it appears to happen at random voltages. It also eliminated my batteries as a cause. 

I'm worried that people might buy one and not realise it's faulty, because the light still works, but with considerably reduced output. 

Not sure what to do now, I've paid for what is supposed to be a well made light, but keep getting duds. I wonder if there was a faulty batch, hence the 2 lights with the same fault. I noticed also that someone else got a light with the same fault as my first one, where the pressure of the tailcap spring would stop the light from working. 

Such a shame to see these problems, these are really nice lights when they work. I'm certainly not posting here to damage their reputation, but I'd also like people to be aware that there appears to be a number of faulty units coming out of the factory at the moment.


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## Woods Walker (Jul 24, 2009)

I wonder if it is going though low-high and then to med mod all in one press. Mine would do this and also acted like I was pressing the switch twice. So sometimes it would go off or to the next mode beyond what I wanted against my will just after using the clicky. I got to thinking that the switch was hitting the boot and going off. So Pulled up a bit on the rubber boot (which didn't move to my eye) and it stopped. Now everything is good. Beyond that few flakey days it has worked like a champ. Maybe clean the contacts (standard statement) and try to grip the boot cover and pull up a bit. Mine has also performed well in the rain etc so thinking those issues have been resolved.


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## FlashInThePan (Jul 24, 2009)

Very interesting!

I've also had problems with my 501w. I love Zebralights, and have two that work flawlessly. However, my new 501w stopped working almost immediately after I bought it. I turned it on twice, and then when I went to turn it on a third time, nothing happened. I tried new batteries, using ProGold, letting it rest - nothing seems to work. Zebralight's given me a RMA, and the light's headed back tomorrow for repair.

Sorry to hear about your repeated problems, Fox - what a shame! Zebralights are phenomenal; I hope this was just a bad batch. 

- FITP


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## Woods Walker (Jul 24, 2009)

FlashInThePan.

Man that is a sad story. You didn't even get a chance to enjoy the warm tinted goodness.


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## Foxx510 (Jul 24, 2009)

Woods Walker said:


> Maybe clean the contacts (standard statement) and try to grip the boot cover and pull up a bit. Mine has also performed well in the rain etc so thinking those issues have been resolved.



Thanks for the suggestions, but it's actually a faulty HIGH mode, as the other two modes are still there at ~30mA and ~110mA. The HIGH mode will be 440mA on one cycling of the modes, then the full 1100mA the next. Contacts are good, no flickering that would indicate a bad connection. 

I hope they get the QC sorted, there's a great opportunity here for another manufacturer with a decent factory to make a similar but reliable product and grab their market share.


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## Foxx510 (Jul 24, 2009)

FlashInThePan said:


> Very interesting!
> I tried new batteries, using ProGold, letting it rest - nothing seems to work. Zebralight's given me a RMA, and the light's headed back tomorrow for repair.
> 
> Sorry to hear about your repeated problems, Fox - what a shame! Zebralights are phenomenal; I hope this was just a bad batch.
> ...



Thanks. On your faulty one, try removing the tailcap and using a bit of tinfoil to connect between the battery negative and the bare edge of the end of the barrel. It may have the fault that my first one had.


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## half-watt (Jul 24, 2009)

Foxx510 said:


> ...This fault is a strange one, as with the last replacement it will randomly start up in a "not quite HIGH" mode which pulls around 440mA...



i've experienced something similar with some other lights. their construction is quite a bit different, but maybe(???) what i've found to be the problem w/them might help you (and possibly others).

my only real crab with the LiteFlux lights is that SOMETIMES, when i change out the cell for a fresh one, a poor (i.e., high resistance) connection is made when the light is screwed back together. 

this has happened with all three models that i have (viz. LF3XT, LF5XT, and LF2XT), and is present in all the units that i have (i have 2 or 3 of each).

on those occasions where the high resistance connection takes place, i need to unscrew somewhat the head or tailcap (depending upon model) and retighten and repeat if needed until a better connection is made.

now, the ZL has a much simpler design, in this regard, but perhaps the tailcap (or something else in the ZL assembly in the head) is intermittently making a poor connection, or something not positioned quite right in the head is intermittently forming a high resistance shunt/path to somewhere that it shouldn't.

hope this info helps someone.


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## Foxx510 (Jul 24, 2009)

Thanks half-watt, but it's def not poor contact on these units unfortunately. It's looking like I can induce the fault by cooling the light in a fridge, and then make it come good by warming it up. If I had to guess I'd say there's a bad batch of components gone into these lights like a FET or similar. Counterfit electronic components are a big problem in China, I guess that's always a possibility.


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## cheetokhan (Jul 24, 2009)

I just gave my 501W an hour in the freezer and it still works correctly. At first, it seemed a bit dim, but that was just due to the frost on the lens
It still pulls a little over 1A from the battery.


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## Foxx510 (Jul 24, 2009)

Well they are going to send out another replacement. I'm glad at least that they try hard to keep customers happy when things go wrong, lots of companies wouldn't bother.


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## Viper715 (Aug 2, 2009)

Figured I would throw my hat in the ring oh I mean faulty 501W in the trash. I bought it on the 13th. It has worked well up untill a week ago and then I noticed a diminished out put but thought I used it alot so the battery is getting weak. But then I would turn it on and it was brighter. I tried a new battery and had the same issues.If I would turn it on and it was dim I could just lightly flick it with my finger and it would flicker and get brighter. I thought maybe bad connection but I tried everything to no avail. Then today I used it in a crawl space fixing some wiring and it went poof. Of course I had back up but not as nice of a profile for the job but the backup a Nitecore Extreme got me out of the dark. I tried several batteries anit is definantly dead. I contacted my retailer and am sure the will replace it but my quesstion is it really going to be a fixed one or have the same fault. It seems that it is not uncommon from this thread. I am wondering if I should just sell of the replacement and wait for a reliable light to come out like maybe the Saint. Has there been any indication that ZL is awair of the problem and working on a fix?


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## DonShock (Aug 2, 2009)

I had a bit of a problem with my H60 for a while. I use it every night at work and recharge it once a week. I noticed that the first night or so, after recharging, the contact seemed to be intermittent for a while but then it would start working fine. Once the intermittent operation stopped and it came on steady, it would stay fine until it was recharged. After trying a couple tweaks to find the problem, I seem to have found the cause and a solution. The problem seems to be poor contact between the body and the spring plate inside the tailcap. Even though the tailcap was tightened as much as possible, since the contact was only made on the thin edge of the end of the body tube, it would make and break contact as it was jiggled. Eventually, it would move around enough to provide steady contact until the next time the tailcap was removed to recharge the battery. My temporary solution has been to use a paper clip bent into a circle and inserted into the tailcap to make steady contact between the body and tailcap. For a more permanent solution, I am going to go to some copper wire and soldering it into the tailcap.


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## CathastrophiX (Aug 3, 2009)

Cut the spring instead (H60). I used to put a copper ring in the tailcap also.
If you use protected batteries, the spring is too long, it can't compress enough.


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## Foxx510 (Aug 3, 2009)

Well I got my replacement today. 

The good: It works properly, so far. 

The bad: It's a secondhand one that has been repaired. You can see marks where the SS ring has been levered out and the anodising has been scratched. The lens and tailcap are scratched and the tailcap spring plating is worn. 

So in the end I still didn't get what I paid for, a new working H501w. This will have to do though, I guess. Although they've tried to make good, and I thank George for his efforts, I still couldn't recommend a ZL to anyone, the QA just seems to be non existant right now.


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## Foxx510 (Aug 4, 2009)

Oh, wait. If I put it in the fridge it has the same fault as the last 2, dimmer and draws 480mA until it warms up and you cycle through the modes. It should work at 4 deg, shouldn't it?

So make that my 4th faulty light.

News just in: The pushbutton is faulty also. Mode changing is erratic.


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## wapkil (Aug 4, 2009)

Foxx510 said:


> Oh, wait. If I put it in the fridge it has the same fault as the last 2, dimmer and draws 480mA until it warms up and you cycle through the modes. It should work at 4 deg, shouldn't it?
> 
> So make that my 4th faulty light.



It seems then that this behavior is repeatable for different lights. Not good, I wouldn't like my zebras to dim when it's cold outside. I think I'll also check them.

How long were you keeping yours in the fridge? The 4 deg. you wrote above is 4 deg. Celsius, right (not Fahrenheit)? Were you using a battery that was in the room temperature or one also cooled in the fridge?


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## Foxx510 (Aug 4, 2009)

4 deg celcius, battery out of fridge. Same problem if I leave light outside at about 6 deg celcius. As far as I can tell it only happens at startup when the circuit board is cold. Once running and warmed up it should stay bright. I just don't trust them though knowing there are probably substandard/faulty mosfets in there. If you don't have a current meter, just stick it in the fridge then once cooled cycle it through the modes holding the button down while your hand warms it up. You'll see high mode pop up to full brightness when it's warm enough, if you have a faulty one.


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## wapkil (Aug 4, 2009)

If all zebras that you tested are sensitive to cold, it seems that it's not a random error but the result of their design or components choice. I'll see how mine behave. I have a bunch of DMMs to test them  

Could you write approximately how long were you cooling them in the fridge and how long it took (in the room temperature, I assume) before they started to work normally?


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## Foxx510 (Aug 4, 2009)

They were in the fridge for about 10mins, it doesn't take long given the aluminium body. The time to start working properly depends on the environment it is in, if it's in your warm hand it might only be a minute, free air might take a few minutes. Some are more sensitive than others, I have three here that are all faulty and all take different amounts of heat to come good.


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## wapkil (Aug 4, 2009)

I couldn't repeat this problem with my zebras (H501 and H501w). After more than half an hour in the fridge they were working normally with an Eneloop cooled inside them and with a warm one (1.10A-1.15A current on high).


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## Foxx510 (Aug 4, 2009)

Interesting, when were yours purchased?


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## wapkil (Aug 4, 2009)

Foxx510 said:


> Interesting, when were yours purchased?



They were shipped to me on March 26th.

EDIT: the regular one was, the neutral one came around a week later.


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## Foxx510 (Aug 4, 2009)

Ok, the ones with this particular fault were from June this year. My first unit had a different fault. All of the replacements with this fault show some damage to the anodizing near the SS ring. I'm not sure if this means they are repaired units or all H501s have that as part of the manufacturing process.


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## wapkil (Aug 4, 2009)

Foxx510 said:


> Ok, the ones with this particular fault were from June this year. My first unit had a different fault. All of the replacements with this fault show some damage to the anodizing near the SS ring. I'm not sure if this means they are repaired units or all H501s have that as part of the manufacturing process.



My H501w has a tiny ding in anodizing near the ring. I haven't looked at it in the H501 and now it has a bigger "headcap" glued in so I cannot check. BTW, when I was performing my runtime tests for the high mode I kept the light in the fridge and it worked normally for the whole test duration.

I think that someone wrote that his H501 is brighter with Li-Ions than with NiMHs. When I tested mine, in the high mode it was half as bright with Li-Ions (compared to a NiMH). Maybe ZebraLight changed something in the circuit?


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## Foxx510 (Aug 4, 2009)

Yes I suspect that the scratch in the anodizing near the ring might be normal, but it's clearly much worse on this latest replacement and the ring itself is dinged, so I'm guessing it's a "repaired" unit. 

I'll try mine on li Ion voltages tomorrow and compare brightness.


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## Woods Walker (Aug 5, 2009)

I don’t see any scratch in the anodizing near the ring unless it is so small my eyes can’t see it. The only issues I had with the switch acting up seemed to disappear per method in post #2. I used a H501 and H501w on the AT the last two days and they worked great. The only issue was the H501 turned off pronto once the Duraloop was drained as served the purpose of an area camp light and got a lot of use. Took some photos of the H501 used in the field and if they came out right will post them in the ZL pic thread. On the issue of cold weather ZL use I test things in the field on the freezer. I don’t know if there is a correlation as cold is still cold. The ZL H50 was used during a winter pulk trip on the AT. It was around -5F but could have been colder. True the light was running on medium sometimes high however was taken from a very cold pack. In fact everything was very cold and ever got a little bit of frost nip on my fingers cutting wood for the stove. The H50 worked just fine. The H501s have been used less as these are new so can’t speak of winter field use with them. I will know more about that later this year.


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## Foxx510 (Aug 6, 2009)

Thanks WW. I'm sure the scratches vary from unit to unit. Good to hear your units are fully functional. I think I will relegate my faulty units to emergency candle usage and build/mod something that I trust to work.


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## wapkil (Aug 6, 2009)

Foxx510 said:


> Thanks WW. I'm sure the scratches vary from unit to unit. Good to hear your units are fully functional. I think I will relegate my faulty units to emergency candle usage and build/mod something that I trust to work.



I seem to remember that Woods Walker ordered his H501w around the time when I ordered mine (i.e. soon after they appeared). If there are different batches, we would have the same then. Foxx510, have you compared the brightness with NiMHs and Li-Ions in your zebras?


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## Foxx510 (Aug 6, 2009)

I can, but I'm not sure how reliable it will be given they are faulty units. I'll go see what happens and report back.


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## Foxx510 (Aug 6, 2009)

I don't think mine are working right on 4.1volts, the current draw was 12mA, 70mA and 140mA and brightness was craptacular. I swear one of these was super bright on a higher voltage, but it may have been when I ramped up to 4.1v from 1.5v. (I'm using a powersupply for these tests)


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## wapkil (Aug 6, 2009)

Foxx510 said:


> I don't think mine are working right on 4.1volts, the current draw was 12mA, 70mA and 140mA and brightness was craptacular. I swear one of these was super bright on a higher voltage, but it may have been when I ramped up to 4.1v from 1.5v. (I'm using a powersupply for these tests)



For me it was 14mA, 72mA and 134mA, measured with a Li-Ion battery. And yes, the brightness in the high mode was ~40% of the NiMH high mode, so it looks quite similar. I'm pretty sure I saw someone writing that the zebras are brighter with Li-Ions but maybe he was just guessing...


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## Foxx510 (Aug 6, 2009)

Yes I thought it was brighter too but I think that was a brain failure on my behalf. 

I wonder if I'm getting the Li Ions lower high brightness on NiMH when mine don't work properly. That's a strong possibility.


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## wapkil (Aug 6, 2009)

Foxx510 said:


> Yes I thought it was brighter too but I think that was a brain failure on my behalf.



As you wrote, it may be also possible that when you ramped up the voltage, the circuit went to direct drive instead of the buck mode. It may be quite surprised when the battery it uses suddenly raises the voltage and changes the chemistry


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## Foxx510 (Aug 6, 2009)

Yes I'm sure I confused it! 

So why would the HIGH mode be so much lower on Li Ion? I assume it's a limitation of the circuit, but it kind of makes the use of Li Ion a bit pointless, unless I'm missing something obvious....


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## wapkil (Aug 6, 2009)

Foxx510 said:


> Yes I'm sure I confused it!
> 
> So why would the HIGH mode be so much lower on Li Ion? I assume it's a limitation of the circuit, but it kind of makes the use of Li Ion a bit pointless, unless I'm missing something obvious....



I don't know. I was also surprised when I measured it. I think it is quite unusual for flashlight drivers.


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## lebox97 (Aug 6, 2009)

I thought I read somewhere that Li-ion high was lower then nimh - BUT 2-3 times the runtime? :shrug:




Foxx510 said:


> Yes I'm sure I confused it!
> 
> So why would the HIGH mode be so much lower on Li Ion? I assume it's a limitation of the circuit, but it kind of makes the use of Li Ion a bit pointless, unless I'm missing something obvious....


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## Foxx510 (Aug 6, 2009)

Yes you'd get around 5.5 hours with a Li Ion on HIGH. I can't see the advantage when you can run a NiMH on MED with a similar output for ~15-19hrs.


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## wapkil (Aug 7, 2009)

Foxx510 said:


> Yes you'd get around 5.5 hours with a Li Ion on HIGH. I can't see the advantage when you can run a NiMH on MED with a similar output for ~15-19hrs.



In my tests the Li-Ion high was almost 3 times brighter than the NiMH med so there was a clear difference. I wrote there that it's possible it may be useful sometimes but to be honest I don't see me using it and I would prefer a "normal" (NiMH) high brightness.


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