zelee, what kind of fungi? Have you tried bleach to clear it?
look like a white spore,try to clean it with warm water+soap and dry it properly well it works for a while and when i store it at my drawer about a week same problem happen.
nitecore should make a switch like tm series for ea4 
Try alcohol, should kill most living things on that switch boot.
Hi atbglenn
Sorry to hear about your issue but I think the reality is that it's just a matter of time for all of us. There has been waaaaay to much documentation on the Nitecore EA4 switch issues to ignore.
It's a crappy mistake from a company that should have done better at the price they are asking, especially given their MAP stance discussed in other threads.
The biggest problem seems to be the blue flashing voltage indicator which I franky think is a wank! To achieve this they had to make the rubber boot so thin as to be a ticking time bomb. The first indications of problems were in the form of melting and ballooning switch boots. Your problem is the next symptom to be expected logically.
Unfortunately, to date, it seems Nitecore has thier collective heads buried firmly where the sun don't shine! I know of no official comment or acknowledgment from them on this well-publicised defect and I've followed the discussions here and on the other side pretty closely. There is a lot of ill-feeling towards them at present.
If anyone can point me at an official Nitecore response that would be fantastic. Let's hope Calvin at IS has better luck.
In the meantime, you should perhaps look this thread at CPF which describes a method for replacing the switch boot yourself. Not everyone's cup of tea perhaps but a useful read all the same.
I for one will follow this thread to the finish line :exmark:
So I had a long discussion with my sales rep. Nitecore has apparently been keeping track of and hearing about the issues with the boot. The have already changed the material on the boot from a "TPR to silicon dioxide." The newer EA4 batches should all have the improved button. As for the old ones, I believe the number of people who actually have the problem may not be as extreme as some people think. I am NOT saying the problem doesn't exist, but the amount of complaints we have received have been minimal based on the number of EA4/EA4W/EA4L2 we have sold. Since it is too difficult to replace the boot by ourselves, the policy is simply to replace any EA4s that have cracked or bubbled with ones from the new batch. Unfortunately we don't have any of the new ones at this point in time but will be acquiring some in the near future.
I would like to reiterate that the current material on the EA4 have felt and lasted fine in my experience, I have several "floor model" EA4s and their variants that are as old as when the product line first came out with no apparent damage. It appears to be a mileage may vary case with people and their various environmental and usage differences. I hope this help answers some people's questions.
Well, that’s one way to solve the problem. Now, does the cost of the new light fall on IS or Nitecore? It better be Nitecore.
Thanks for your post Calvin. It is great to have good vendors going in to bat for us.
Did Nitecore by any chance make a comment about what can be done for those who didn't buy their lights from you / IS?
(Not your problem, I understand but I will ask anyway.)
It is quite reasonable to assume they don't want users cracking open their lights for a DIY fix but it is also a fact in this day and age that many of us purchase online. Postage being what it is, return to an International vendor is simply not an option and not all countries have bricks and mortar stores that can carrry the lights we want at a competitive price.
If the number of problems is actually as low as they (or you) believe, then surely it would be smart business to end the ill-feeling by acknowledging their mistake and offering to replace (including shipping) the light for those affected. This is clearly not a "regular warrantly" type problem. Reputable manufacturers in other industries will issue product recall notices (though admitttedly this is mosty for safety issues.)
Since they at least appear willing to talk to you, would it be possible to ask them to provide a range of serial numbers for the lights that have the original TPR boot? There are quite a few of us who are now reluctant to use or carry an otherwise very nice light because of the fear of ruining it. Being able to identify which boot we have would be a good start.
This is at least much better news than being told by Nitecore to "see if your dealer has spare parts" or "prick the button with a pin to make holes". If they are indeed following these threads and now have a fix, it would be smart business for them to step up and release some official comment.
I assume that all vendors will have to do a similar warranty service as it is part of the responsibilities associated with being a dealer/distributor. Talk is slow as my sales rep is not in a position of power and has to repeat info to me from engineers and managers.
Just want to go on record as another EA4 owner that has a cracked boot. The more of us that speak out the better.
By the way, I got mine from Fasttech, so shipping the light back is probably not an option. Nitecore needs to recall these lights and repair or replace them.
This is bad news indeed, really hope Nitecore will recall their EA4 & EA8 series in order to maintain good reputation in premium flashlight category.
Considering they are not an authorized Nitecore vendor would probably make the situation more difficult.
You ship them to the Miami office, so you don’t have to worry about international shipping. But just because you’re shipping it to their US office don’t expect anything like a fast turn around. It basically saves you money, but no time.
By the way, my switch is fine so far.
No wonder theres plenty of cheap EA4 on e bay with threads like this going on. vote with ya wallets i say and get a sunwayman d40a… or if your more flush in the wallet a eagletac GX25A3. or wait and see what zebra…niteye… 4sevens brings to the table too 
SWM D40A I chose, but still I very much prefer battery carrier unibody EA4 design.
Just the switch cover that keep me away from, but D40A has Moonlight mode which +1 back to SWM 
Great news! Just got an RMA# from Craig at Illumination Supply! Once he gets it, he's sending me a replacement. Can't beat their superb customer service!
Thanks Calvin and Craig!!
way to go glen,but that did not solve entire problem are we?since same problem will occur again in the future.
At least Illumination Supply stand behind the products they sell. Hopefully the replacement will hold up a lot better. Time will tell my friend :)
Thats great news!! Great customer service!!
Great news Glenn, and kudos to the IS team for the prompt service, even as the details are being hashed out with Nitecore!
To anyone who will try a similar RMA request with Fasttech, let us know how it goes. It would be good for all to know how these types of things are handled.