Just to be clear:
The current rating of the charger is not related with this issue!
There are - in my opinion as an electrical engineering student - two possibilities:
Most chargers are switching power supplies, it might be the case that the hight frequency is not filtered enough and the touchscreen is confused by that. I think this is unlikely since nobody reported this issue for powerbanks which use switching power supplies as well.
The charger’s output voltage has a potential to protective earth. And since you are also (with a more or less high resistance) connected to the earth, the touchscreen is confused. I think this is the root cause.
I’m not a charging expert, but I think the only possible solution is using an other charger which doesn’t have this issue.
Since I don’t have this issue, I cannot do tests myself, but I do have a theory for a workaround: Isolate yourself. Stand on a isolating material, like a plastic plate. The problem shouldn’t be there any more.
I have that problem with my Fairphone since upgrading to OS 1.3.6 on one of my chargers.
I had similar problems with (other) chargers with my HTC Desire HD, but not with this one.
Does anyone has this problem?
Anoying buzzing and flikkering … repeatedly en continiously while charging
It only seem to appear when my battery is almost empty/low
Screen becomes unusable, like described above
It stops after rebooting or a few minutes of charging
Slow charging anyway
Low battery after using fp2 for 3/4 day: a few short calls, a few internet searches and a 15 or zo sms messages sent … Gps/lotion off, Bluetooth off etc.
Both the unusable screen and the slow charging indicate that you should try another (better) cable to charge your FP2. Most people get lucky and the first cable they try works fine, but some reported that they tested 3 or more cables until they found one that works without causing troubles.
Make sure you have a good quality data cable (not just a charging cable).
I couldn’t find this reported anywhere so here it is:
I have a double plug socket with two dedicated USB ports for charging USB devices. It’s rated as 2.1A / 5V. The phone (FP 2 / Android 5.1) seems to charge as expected, however the touchscreen becomes practically unusable when connected to either of the 2 ports available: it becomes hyper-sensitive and often completely unresponsive. The only way to carry on is to ‘lock’ the phone, then unlock it, but even then the problem persists a few seconds later.
If it helps, the exact model of the wall socket is here
Any ideas on how to solve this? I have two of these USB-containing sockets and the problem is repeated on both of them, ruling out a problem with the sockets themselves.
I’m not sure if this list of workarounds will really help, but if you have a spare cable for testing, it’s maybe worth trying. Let us know if changing the cable somehow helps!
I’ve tried a second cable, same result. I should add that charging via the normal plug socket or via USB to a computer works fine, it’s just the dedicated USB ports that cause the problem.
The workarounds didn’t help, unfortunately - I had already changed the delay from short to medium.
From your second link, it looks like others may have experienced the same kind of problem. Please feel free to move this into the same thread.
I spent a lot of money searching for my best FP2-charger:
Vegavolt-A621
It is not originally produced any more but I found it on several flee markets and also on other elelktronic markets, especially the cheaper ones. (on my flee market I payed 5 EU )
Since I buyed now 3 different charges with 1 and 2A I only can stress that all effects depends on the charger.
As I wrote, the unusable screen while charging depends on the charger, not the cable with my phone. I have a few good data-cables and they all work depending on the charger I use.
I do not have these problems while charging via computer or my little power bank. (Also not depending on which cable I use) But I usually don’t use my computer as a charger.
I have only found one cable that does not work well…
I installed a new power outlet in my desk (this one). When I charge my Fairphone 2 from one of its USB ports, the touchscreen becomes totally unresponsive. When I unplug, and turn the screen off-and-on-again, touches are recognized again.
When I charge from my laptop, or a different power socket with usb adapter, I do not experience the same problem.
This may or may not have something to do with the recent update to 1.4.2. I don’t remember if I ever tried to charge the phone through the new outlet before the update.
What could be causing this? The USB ports on the new outlet are specified as 1000mA 5V. Are those the wrong specs?
Maybe it has to do something with grounding? Is your laptop power supply “two pin” and your new USB outlet/power supply “three pin”? Just guessing, I have no clue how ground loops work or if this could even affect the display.
Can you compare a grounded vs non-grounded usb power supply with your FP2?
Interesting. The outlet is grounded, and the laptop is not, as you guessed. As for grounding myself, that’s a bit unpredictable. Touching a radiator usually grounds you, right? It doesn’t seem to make a difference.
I would open up the outlet to have a look, but that requires a three-pronged screw-bit, which I don’t have on hand.
Anyway, this still sounds plausible. Is there a permanent solution to this problem?
Has anyone who is affected by this issue noticed improvements since the 1.6.2 update?
My FP2 now seems to be significantly more responsive. The touchscreen still sometimes stops responding, but before 1.6.2 it was basically unusable while charging. The release notes don’t mention this, so it might just be a coincidence.
No, it is not a grounding issue. I experience the same flaws as you do, and I do experience it with a wide range of USB power outlets, some definitely on the more expensive side (Anker, Samsung) and definitely not grounded, while others seem to be not quite as bad.
Which USB power outlets work and which do not with the FP2 does seem to be magic and black art more than anything with specifications…
Since I upgraded my FP2 OS to 1.6.2, whenever my phone is charging it’s completely unresponsive.
I have to remove it from charge, press the unlock/lock button and then it works.
But also, it keeps randomly restarting.
since a longer time (e.g. for several FW Updates up to 1.6.2), using the FP2 while charging works fine when charging via USB or charger (HTC, Input 100-240 V, Output 5V, 1A).
But, whenever I use my charger in a train (Deutsche Bahn ICE, Intercity etc.), the touchscreen freezes after a short time. I have to switch off and on my phone. Charging and using the phone simultaneously is impossible. The charger works fine with other phones even in trains.
So I assume the internal charging unit of FP2 is too much sensitive against fluctuations of current which are typical for those power sources. No regular charger can compensate power fluctuations in total, so a phone has to be tolerant against power instabilities.
I usually don’t experience this issue. However, every time I’m traveling in a German high-speed speed train ICE the touchscreen immediately stops working while charging. Has been in every ICE so far, no matter which cable I’m using or which generation I was traveling with. In every IC (older and brand new double-deck trains) equipped with power sockets, however, this hasn’t been the case and charging worked perfectly fine for me. No idea what that means, just an observation. So if any of you are going to travel in a fancy ICE - better take your power bank with you!
I have the same problem in France and this is really annoying.
It’s strange that the solution is to buy a new charger when the politic of fairphone is to be able to reuse our own charger…
