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Help Unresponsive Touch Screen While Charging (OEM Charger)

M

mooga2324

Lurker
Does anyone else's touch screen become unresponsive when the Epic is being charged? My touch screen gets glitchy and only responds to a fraction of touches.

I just received mine yesterday and I've already spent more than 6 hours trying to troubleshoot this issue. Most of the google searches that I've found have to do with cheap 3rd party chargers, but I'm using the OEM Samsung charger.

I thought it might be the charger, so I went out and purchased 4 different chargers today, but none of them fix the issue.

I also ordered another Epic for my wife at the same time, and her Epic has the same problem, which suggests that it's not a defective phone (unless they both came from the same batch).

To confuse things even more, I've been able to isolate 2-3 outlets in the house where this problem doesn't happen. The problem also doesn't happen when I charge at work, through a car charger, or via USB from the laptop.

I'm inclined to think it has something to do with the outlets in the house. However, I've never heard of any issue like that and the house is relatively new (built in '98).

Does anyone here have any thoughts? Thanks in advance...
 
i had the same issue with an aftermarket charger, but not with my other charger (usb cable and adapter that came with my palm pre). I just stopped using that particular charger
 
Confirmed and tested on 3 aftermarkets built specific for the epic. OEM out of box charger worked fine. All aftermarkets failed 100%. Screen wouldn't really work unless of the charger was unplugged. Tested both rooted and non-rooted. Superior communications charge had touch functionality working fine on the dock. That was the only difference.





Cheers,




New User
Epic 4G (rooted)
Overclocked (1.3ghz) ;)
 
I had the same problem with AM chargers and launcherpro. My wifes phone with TW worked ok I finally got mine to work ok with some of them by turning on usb debugging. I tried wall outlets, surge Outlets, and battery supplied Outlets all with the same outcome. Funny thing is I tried a am car charger in the car and it worked fine, but the same charger plugged into a 12v to 120v adapter in the the house made the screen useless or it activated itself.
 
I am experiencing this with an aftermarket charger as well. Seems that there is a voltage spike or something of that nature that the screen doesn't like.

Also, when my phone is plugged into one of these 'bad' chargers, whenever i get a notification, instead of using the tone(s) that i set, it give off this awful, nagging, siren ring sound until I hit a button to acknowledge it.

For those with the screen responsiveness issue, try getting a notification when it's acting up and see if it's a weird sound for you as well...

Thanks,

Matt!
 
Check the output voltage on your charger, if you can. I've got a couple different ones and I've experimented with Verizon and various aftermarket chargers. I did figure out the screen seems to act the worst on anything registering as a "USB Plugged" charger outputting more than 500mA. I think this is all about the internal voltage regulation.

I'm still going through voltage apps to try and get real numbers, but I've discovered charging from the Sprint/Samsung branded car/wall chargers works the best, probably because they properly regulate their own voltage. Samsung's branded AC charger lists at .7A and registers as "AC Plugged" in the phone, doesn't matter that it uses the same USB cable as all the others. The Verizon charger worked the same. Also noticed if the charger registers as "AC Plugged", the phone doesn't ask to be unplugged when charging is complete.

Aftermarket chargers typically register as "USB Plugged", which may make some difference in the way the phone regulates the charge. The phone doesn't refuse them, but these are where the screen sometimes reacts differently. I have five generic USB chargers for car/home. One is not listed (I think it was on a sticker) one is rated 300mA, one is 500mA, one is 700mA, and one is 1A. The two lower rated chargers behave normally, the two higher rated chargers and the unknown cause the screen to screw up. The 1A charger is the worst.

Also there are differences between computers. Even the official branded USB cable has no voltage regulator, so it's at the mercy of the USB port. Some USB hubs cause the problem, and directly plugging into one particular computer I have access to also causes it, so I'm guessing that computer possibly puts out more than 500mV at the USB port. Using laptops as chargers generally works fine for me so far.

The biggest problem definitely came from using the listed 1A output chargers, they make the screen the worst. It goes totally haywire, zigzagging jagged lines with random touch points. I have to unplug the phone to unlock the screen.

No app I've found shows the input voltage or the internal balance between charging and device usage, so I'm not sure what's going numberwise. I only have battery charging rate, which is always between 133 and 166mV.

My guess is "fast" chargers / high output chargers and unknown USB output voltages are causing the problem.
 
You may find this amusing.. One was done while charging via USB cable to my Laptop. The other was done with a generic 120V AC --> 5V DC/1A USB wall charger (using the same USB cable).

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My comments- the epic 4g came with a 1A charger. The third party charger is only 550mah. When the phone is charging, it might be that when charging, the phone switches to power from the external source. Thus if the external charger is not high enough, the screen function controlled by the software/operating system code sees that the voltage is not high enough and freezes the screen. It is not accessing battery because focus is on recharging the battery, My screen also works fine when oem charger is used. Just a theory but I think it is function of the software os controlling what power source is available for screen function when charging.
 
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