Nitecore EA4 Ballooned/Melted switch Repair Write-Up

For everyone having issues with a ballooned/melted switch on the Nitecore EA4:

This switch melting problem seems to be a fairly common issue for these lights. Google search for "Nitecore EA4 melted switch" and you'll find several hits. It is unclear yet whether this is caused by air expansion due to heat, battery venting, or both. In my case I had the light off in its holster with Primaries in it and it swelled and deformed pretty quickly. I'd never had any issues before running primaries or rechargeables, so I'm inclined to think that it is trapped air inside the light expanding and causing the issue.


After about an hour inside my vehicle on an 87 degree day my switch swelled up and distorted badly to the point of being non-functional. It looked like a festering boil on a rhino's backside. Mentioning this problem to Nitecore on their Facebook page got a dismal response. The text from the June 12th, 2013 post is as follows:


I left my Nitecore EA4 in the passenger seat of my car while I grabbed some lunch yesterday. It was about 87 degrees; not terribly hot. When I got back to work and pulled the light out of the holster, the power button was swollen and melted and the light no longer worked at all. The light was turned off and in its holster while it was in the car. I own over 60 different flashlights (I'm a member of www.candlepowerforumscom and edcforums.com), and this had quickly become one of my favorite lights. How do I go about getting it repaired/replaced? Thank you!
Like · · Wednesday at 3:35pm
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Nitecore: Hi Tom, you could try go back to where you purchased your EA4 and ask them if they have some spare parts to buy or repair.
Like · Reply · Yesterday at 7:50am



I bought mine on Amazon about two months prior, so I was past the point of returning it to them. Feeling like I had nothing to lose, I decided to see if I could fix the bugger myself. After an embarrassing attempt to unscrew what I thought were two different sections of the body, I figured it out. Everything comes out the front.


The other important part is that you will need some kind of rubber boot to take the place of the ruined one. Given the design flaw, I'm not sure that a factory part is your best option. In my case, I used the switch boot from one of my cheap AAA DX lights; specifically the Richuang RC-7001, which runs $2.90. Other AAA clicky boots may work as well.

Please note that I make no guarantees that you will not further damage your light be following these instructions. What worked for me may not work for you. Some force is required to dislodge the main board/LED assembly, and this force could crack the driver board. I will not be held responsible for anyone causing damage to themselves or their lights by following these instructions, which you do at your own risk.


Now back to the Nitcore…


Referencing the excellent images in this post will help you understand the rest of the instructions.
http://www.candlepowerforums.com/vb/showthread.php?351365-Nitecore-EA4-Pioneer-review-(cool-white)&p=4111468&viewfull=1#post4111468

• Unscrew the silver bezel at the lens.
• Take out the clear flat gasket.
• Remove the glass lens.
• Using a sharp point of some kind, carefully pry the black o-ring off the top of the reflector. Unless you take this off first, the reflector is hard to get out, and if forced out, could damage the o-ring.
• Remove the reflector. Be careful as there is a small round black disk at the base of the reflector, about 1/3 inch in diameter, with a square hole in the middle of it, the goes around the LED.
• Remove the large white ring that sits on top the heat sink board. It is beveled on the edges, so pay attention to which way it comes out.
• At this point, take a 6" extension for a socket wrench and insert it into the battery end of the light until it meets the black insulating plate that fits around the battery contacts on the back of the driver board. Using steadily increasing pressure, push the extension until the driver board, heat sink board, and LED and star come out as one unit. They are assembled onto a clear plastic housing that keeps them together.
• As you remove the above assembly, be careful to watch for a rectangular clear plastic piece and very small black plastic plunger that together make up the mechanical part of the switch. They may fall out. If not, you can remove them by applying pressure to the outside of your swollen switch cover until the pop loose inside the light housing.
• In my case, I had to carefully shave the base of the RC-7001 switch boot as it was about twice as thick as the factory boot. Patience and a very sharp single-edged razor blade worked for me.
• Now you can reassemble in the reverse order. The rectangular clear plastic piece has the very small black plastic piece inserted into its center hole from the top side (wide part facing up towards the boot). This little black plunger is what actually makes contact with and actuated the electric switch attached to the main board/LED housing.
• Then slip the boot over the top and around the raised ring molded for it. Insert this assembly back in the main light housing and press it into the boot hole until it seats firmly. The clear plastic piece's ends should be touching or nearly touching the metal light housing.
• Insert the black insulating disk that goes around the battery contacts, and be sure to orient it properly based on where the springs will be once the main board/LED assembly is reinstalled.
• Put the driver/LED assembly back in carefully. You have to get a straight on shot or it will hang up crooked on the threads. I found that rolling up a piece of paper and sticking it in the housing and using it a cylindrical shoehorn helped.
• Press the assembly in as far as it will go and test the action of the switch before putting the rest of the light together. It should feel something like the factory switch, with maybe a bit more travel before it engages. If you replacement boot is considerably taller than the factory boot, you may want to put some kind of hard spacer inside the boot to take up the slack.

You should be good to finish on your own from here. Until Nitecore makes the decision to step up and address this gross design flaw on what is otherwise a simply stellar light, this may be of help to some. Hopefully they will see this post, among others of those having this same issue, and change the design.

macgyver35 said:

Given the design flaw, I'm not sure that a factory part is your best option.

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ye.
why replace something which had failed on you with the identical Nitcore replacement part?
spare third-party rubber boots can be purchased from online stores, no prob.

macgyver35 said:

For everyone having issues with a ballooned/melted switch on the Nitecore EA4:


.......The other important part is that you will need some kind of rubber boot to take the place of the ruined one. Given the design flaw, I'm not sure that a factory part is your best option. In my case, I used the switch boot from one of my cheap AAA DX lights; specifically the Richuang RC-7001, which runs $2.90. Other AAA clicky boots may work as well.........

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Firstly, thanks macgyver35 for a very detailed post which should be useful to many other EA4 owners, if not right now then certainly the first time they forget and leave it in a car. 87F is certainly not hot compared to what we get here in summer. When it is over 110 in the shade, the inside of a car must be terrible and it isn't always possible to park in the shade or leave the windows down.

I will be loathe to carry my damned EA4 out of the house in summer for fear of this nonsense. It's a great light let down by a stupid flaw. Even more stupid of Nitecore to dismiss or minimise the issue. I even read in here that they advise putting pinholes in the boot as a means to address the problem. Don't know how this would help with the melting part though.

One thing I'd really like to know is the dimensions of the boot you used. It's helpful of you to say where you found one, but if it was possible to get exact measurements I think this would be even better.

No offence to shelm, but simply saying "oh yeah you can get boots online no problem" is not much of a contribution.

It may be too late for you to do this for us now if you've already fitted the replacement, but I had to ask.

Thanks again for this info.

I can't understand why more people haven't taken an interest in this thread even to say a simple thank you. :shrug:

Thankfully my EA4 hasn't shown any signs of having this problem but I'm bookmarking it. Thank you for the write up. With how popular the EA4 is I vote for making this a sticky.

I wish this problem would have been more talked about before I purchased mine, had it been I wouldnt have ever bought it. Even tho mine hasn't ballooned yet how can I trust it not to after all of them that are.

Trevtrain said:

I can't understand why more people haven't taken an interest in this thread even to say a simple thank you. :shrug:

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I think it has to do with the ratio of working EA4's vs those that balloon, has anyone done a count of how many reported balloonings/malfunctions of the switch have actually occurred? Is it like 8 over a 43 page thread? The reason why many are not being as fast to give thanks is most likely the majority are working well... Add in the fact a person with a negative experience is doubly likely to report it than one with a positive. Just food for thought, people go so far now on the forum as to say the EA4 can barely handle heat, really? My two have been near too hot to hold in hand when running for 20 minutes+, no issue, my cool white had to be one of the first 1000 off the line, my NW same for the tint.

Showmethelight said:

I think it has to do with the ratio of working EA4's vs those that balloon, has anyone done a count of how many reported balloonings/malfunctions of the switch have actually occurred? Is it like 8 over a 43 page thread? The reason why many are not being as fast to give thanks is most likely the majority are working well... Add in the fact a person with a negative experience is doubly likely to report it than one with a positive. Just food for thought, people go so far now on the forum as to say the EA4 can barely handle heat, really? My two have been near too hot to hold in hand when running for 20 minutes+, no issue, my cool white had to be one of the first 1000 off the line, my NW same for the tint.

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As the person who wrote the write-up, I think the fact that more people haven't jumped on this thread is due more to the fact that, at this point, it's only been up for 48 hours. And on Father's Day weekend to boot. I don't know what the percentage of switch failures has been, but part of my drive for doing the write-up is to eventually try and capture those numbers in a more meaningful and accurate way.

I do appreciate the feedback and kind words from those thus far. I only ask that if you hear of anyone else having this problem that you kindly direct them to this thread and ask them to chime in so we can hopefully get some response out of Nitecore on this.

Yup, similar story here. Left my EA4 which is about 2 months old in the car with an outside ambient temp of about 90 degF. I went to grab the light to do a home inspection and sure enough a ballooned switch. So frustrating because I really was looking for this to be my go to work horse light. Now I have the light apart, easy enough to do once you remove the pressed in Heat Sink. Now the question is how do I want to repair it. It would be nice if Nitecore stepped up and made available some type of repair option available to at least to those willing to give it a go. I am not to thrilled about putting the same inferior switch design back. My brother was looking to buy an EA8 and my advice was stay clear.

Showmethelight said:

I think it has to do with the ratio of working EA4's vs those that balloon, has anyone done a count of how many reported balloonings/malfunctions of the switch have actually occurred?

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Agreed. I've watched this issue pretty closely and am pretty confident there are less then 10 persons reporting this issue here on CPF. By far the majority of users are not. Both mine are working well, and this light takes heat just fine, run on high a while and temps will far exceed the temps a couple with problems posted here. Mine however will NEVER balloon as I poked 3 small holes with a hot needle in mine to avoid the possibility.

I had the exact same issue on my EA4, finding it melted in the trunk of my car on the road trip down to Blade Show. My buddy and I got to a rest stop at around 3 a.m. and decided to play with the lights I brought with me, and the EA4 came right out of the holster with a molten wart where the button used to be. So, this write-up is quite valuable, and I thank you for it sir.

I will add for informational puposes only that I used a different method of dissassembling my EA4. I make no assertion that it is a better method or less likely to create an issue when dissassembling the light. After removing the bezel and reflector, I unsoldered the two LED leads from the star. I then lifted the star off the heat sink. I placed a small hook shaped tool behind the cut out on the heat sink and pulled the heat sink out. It did take a fair amount of force to free it but it did not bend the heat sink. The circuit board assembly is then free to lift out with your fingers. The switch piston (offending part) will then just press out of the body tube with your finger. Hope this helps with different ideas. Now the fix! I do wonder with the warmer months comming if we will hear more about this issue. Althought it was 90 degF outside my car, I am sure it was considerably warmer inside it when the switch failed. I would also note that the light was loaded with Eneloops for FWIW

86° and sunny right now...I'm real tempted to throw my EA4 in the Jeep to see what happens. Hmm...do I satisfy my curiosity or possibly become irate and ruin my night?

markr6 said:

86° and sunny right now...I'm real tempted to throw my EA4 in the Jeep to see what happens. Hmm...do I satisfy my curiosity or possibly become irate and ruin my night?

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I sure wouldn't risk it....

Divine_Madcat said:

I sure wouldn't risk it....

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I wouldn't risk it either at least without placing a needle hole in the side of the boot as was the suggested fix by others. Would be nice to know the switch is no longer an issue and never having to think twice about is my light in a cool enough environment...

Be cool if you could film it too. Actually, you probably could just keep an eye on it, and if it starts ballooning a bit, you could stop (or for science/documentation keep going).

No problems with my 2 EA4 so far (knock on wood [hope I didn't just jinx myself by saying that]). If my buttons balloon, I hope Nitecore will be courteous enough to send out a new button.

Light Brite said:

I wouldn't risk it either at least without placing a needle hole in the side of the boot as was the suggested fix by others. Would be nice to know the switch is no longer an issue and never having to think twice about is my light in a cool enough environment...

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Again.. the way the boots are melting suggests it is only heat,not so much pressure causing the failures. The rubber on these are very thin, and it wouldn't take much to melt these things (as I have already found) .

I mean, poking a hole may help at first.. but as the rubber melts, it may reseal any hole like that anyway..

I do hope Nitecore is actively seeking a different material for the button cover and will supply the upgraded one to any who encounter a failure or who ask for a replacement for that matter just in case it should happen. So far I have not had mine in a "hot car" but can understand the temps reached in full sun on a hot day even here in Canada.

I don't own one of these, because although no psychic, I have had a slight bad feeling about this light. Maybe it's because of the lower price than normal for a light of this caliber. But up til now most reviews have been good. However, I can't understand why these boots would be swelling or worse yet, melting at temps that would occur in a car on a day in the mid to high 80's! Is it made of chocolate?

I just can't understand how rubber would melt at low temps like this, and I can't figure out what phenomenon would cause pressure to build up inside the light on a hot day. Now, if a car is parked in the sun on an 86 degree day(F), then the interior temp may rise to around 100 degrees or so, but that's still nowhere near hot enough to damage decent quality rubber or plastic, and shouldn't cause pressures to build inside the light, unless these lights are powered by hydrogen peroxide like the torpedoes in the Kursk, and it leaked onto some internal steel and reacted, causing high pressures. But last I checked, they still run on AA batteries, so I'm baffled. Unless the batteries are somehow swelling and leaking causing high pressure, which is extremely unlikely, excessive pressure doesn't seem likely.....

think about all the rubber and plastics inside the average auto, which experience high heat all summer long for years with little to no degradation for a long time. When you realize that, isn't it strange that just a short amount of time in that situation can cause degradation to the boot in this light?

HighlanderNorth said:

I don't own one of these, because although no psychic, I have had a slight bad feeling about this light. Maybe it's because of the lower price than normal for a light of this caliber. But up til now most reviews have been good. However, I can't understand why these boots would be swelling or worse yet, melting at temps that would occur in a car on a day in the mid to high 80's! Is it made of chocolate?

I just can't understand how rubber would melt at low temps like this, and I can't figure out what phenomenon would cause pressure to build up inside the light on a hot day. Now, if a car is parked in the sun on an 86 degree day(F), then the interior temp may rise to around 100 degrees or so, but that's still nowhere near hot enough to damage decent quality rubber or plastic, and shouldn't cause pressures to build inside the light, unless these lights are powered by hydrogen peroxide like the torpedoes in the Kursk, and it leaked onto some internal steel and reacted, causing high pressures. But last I checked, they still run on AA batteries, so I'm baffled. Unless the batteries are somehow swelling and leaking causing high pressure, which is extremely unlikely, excessive pressure doesn't seem likely.....

think about all the rubber and plastics inside the average auto, which experience high heat all summer long for years with little to no degradation for a long time. When you realize that, isn't it strange that just a short amount of time in that situation can cause degradation to the boot in this light?

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Seems like there is three camps, one has 10 members with melted rubber switches, the other has thousands without issue and the third is other people who don't own it...

Showmethelight said:

Seems like there is three camps, one has 10 members with melted rubber switches, the other has thousands without issue and the third is other people who don't own it...

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I think quoting your numbers is a bit flippant.

Your attitude puzzles me a little - there is a clearly documented issue here with a faulty switch boot. It may be a statistically insignificant number in your opinion, but it is obviously a very real problem for those experiencing it. Just because you haven't had a problem (yet) doesn't make it an issue that Nitecore shouldn't be looking at. After all, have you ever heard of a similar problem with any other brand/model of light?

There seem to be two separate issues here. Some have reported ballooning of the switch and some have reported actual melting. But in either case, what type of company marketing an IPX-8 (two meters submersible) light would advise users to put holes in a rubber seal as a "solution?" What kind of answer is "see if your dealer has some spare parts to buy"!

Yes, it is very hard to understand or even speculate about the process that might be causing this. As HighlanderNorth points out, vehicles are full of other rubber and plastics that survive for years. I'm sure we all have other lights that are left in vehicles and haven't had melting rubber switch boots. So why the EA4?

It could be that a small batch of switch boots or the rubber used to make them was contaminated or unintenionally exposed to some chemical that affected them.
NiMH cells can vent hydrogen if reverse charged or overheated. Is there some weird combination of environmental/cell factors causing the cells to vent? The very thin rubber boot on the EA4 would obviously swell more readily than the thicker material used on the typical tailcap clicky. Doesn't really explain the melting rubber though unless some combination of heat and hydrogen is at play. I'm not sure how/what the primaries the OP had would vent.

I don't think anyone is saying "all" EA4s have this issue. But I'm willing to bet that more will show up over time.

Let's just hope your two lights keep on working for you.

I'm totally puzzled as well. Think of all the cheap plastic and rubber you put in your car...and even keep there ALL summer without touching it. For me, this includes $.99 rubber gloves, less-than-paper thin shopping bags, rubber on cheap keychain flashlight my local bank handed out (cheapest thing in the world)...yet all these hold up just fine.

Any chance people having issues are putting them in a warm car from a cold building? I wouldn't think it would cause that much pressure, but I noticed my empty orange juice carton expaned a TON after sitting out of the fridge for a few minutes this morning.