So about 13 mounts after buying my first Fitbit I started getting lines that went across the screen. Everyday another one would show up sometimes more then one a day. I took very good care of my Fitbit I thought and didn't know why It started. once about 50% of the screen was unreadable I thought I would see if there was anything I could do about it.
First: Google the problem. Couldn't find much (big surprise) besides a lot of people having the same problem with the Charge 2 and a few others.
Second: What can I do about it? Only thing I found was to reboot it. "Might work" HAHA No its dead pixels opposite of when you have a tiny dot on your HDTV screen that is always black. In this case a whole line is always lit. A reboot will do noting. There is a physical problem somewhere.
If you want to try a reboot your self plug your Fitbit in the charger and plug the USB into a power source. Then push the button until you fell it vibrate. You should see the Fitbit logo come on the screen with the version numbers below. (I say should see you may not if your screen is really bad)
Third: Will Fitbit do anything for me? I contacted Fitbit. Told them the problem. They had me reboot it twice. Then offered me a new one with a 25% discount.
I didn't take the offer and I bought it from somewhere else with a longer extended warranty for a cheaper price.
Forth: Once I received my new Fitbit 2days later. I set it up. Then I was thinking about trying to fix my old one... I started looking for someone that has taking about a Charge 2 before with some sort of tare down instructions. I couldn't find any anywhere. Only site I found any picture inside the Charge 2 was from this Site. It wasn't very helpful for me but I could see a little bit inside and how it was held together.
Step 1: Disassembly.
From the site I linked above I noticed they opened it from the front. I didn't really was marks on the front that I would have to look at all the time. So I thought I would try and go in on the back side. (mistake number one!)
I didn't notice the four big tabs with a melted clip in the photos so I pried and pried but it didn't come lose. Thought I might of been glued a little so I applied some heat ( just enough to soften the plastic a little) finally it came free. (mistake number two!!) I broke the ribbon cable going to the heart rate monitor sensor and to the charging port. At lest I'm in I thought
I found the clips for the front screen and unclipped them the screen came right off. I made sure to be careful not to break the ribbon cable going to the screen. once the screen was detached I could now look closely at every part or see if there was a noticeable damage. I couldn't find any.
Step 2: Conclusion.
Only thing I could find using my microscope for SMD soldering is some thing that appears like broken traces inside the OLED screen. My guess is for the heat and cold here. I bought this Fitbit in February used it year around til March-April (just over a year) when it started getting lines. I'm in and out a lot (Summer and winter) also have air conditioning in the Summer. From the heat and cold expending and contracting the metals I believe some traces broke.
Not unless you get a new OLED screen that would work with the Fitbit. Most likely we wouldn't be able to.
I am going to contact Fitbit again with my findings and see what they have to say. I'm at lest hoping they will look into this and fix this problem for future watches.
If any of you would like to donate your broken watch to this cause please contact me I would like to compare my findings with your watch. If you have the tools and could send me pictures of the OLED screen by the Ribbon cable that would help a lot also.