Same problem here. Replacing the display with another (working, of ym wife) did not help. Cleaning contacts neither.
What helped a bit was pressing the Phone, back cover off, between my fingers on it’s right side, approx 5cm from the upper edge, from back to front. There is a point where after a few presses the display sprang back to normal function again. Sometimes the display worked,but no touch screen. after a few presses more, the touchscreen worked too. Su I suppose it’s a connection problem too. A 380,- repair isn’t an option here, as I am out of warranty already…
I don’t know if this has been mentioned, but using a non-slim, “fat” cover reduces the chance of the screen going wild, in my experience. Probably because it’s less rigid due to the rubber bumper. But you need to find one that didn’t get screwed…
Over the last few days, my Fairphone 2 developed serious problems similar to what is described in this thread: First the screen occasionally became non-responsive and over a few seconds the screen content got replaced by coloured stripes until nothing of the original content was visible anymore. This could temporarily be fixed by applying pressure or torsion to the phone. Eventually, however, my screen showed nothing but colourful random pixels.
Support told me that the problem is likely with the core module and that a repair would be at least € 223.43. Not a very attractive option, so I tried what @ElKrasso suggested earlier:
I did not use an oven, however. I disassembled my phone completely, took the core module out of the plastic frame and with the heatspreader (black foil) still on I wrapped everything but the display connector into 3-5 layers of standard household aluminum foil. Then I placed this package on a heating plate and preheated it on low power to about 130 °C (measured with a multimeter). At the same time, I set a heat gun to a temperature of 230 °C and let it run for some minutes to reach a stable temperature. Now I placed the outlet of the heat gun a few centimeters above the display connector on the preheated core module and heated it for about 100s. After that, I switched both the heat gun and the hot plate off and gave the core module time to cool down. Now that I reassembled everything my phone is working normally again! Let’s hope it stays like this until the Fairphone 3 is released.
Thanks ElKrasso for your post!
Edit: One thing I forgot to mention: As @Roboe pointed out earlier, there is a rubber frame around the screen connector that must be removed in order to expose the last two screws fixing the core module to the phone’s white plastic frame. My wife’s Fairphone 2, manufactured one or two years later than mine, does not have this rubber frame! Otherwise, the display connector looks exactly the same, it even has the black screw mounted that is meant to fix the rubber frame. I see two explanations for this:
The factory was out of rubber frames and decided the phone might work just fine without them (less likely ).
The failing screen connector is likely caused by mechanical stress between the printed circuit board and the connector. The rubber must be compressed to fulfill its purpose, namely, to keep dirt away from the electronic contacts. Maybe omission of the rubber frame is an attempt to avoid additional stress to the PCB.
Believing more in explanation 2, I did not put the rubber frame back in place when I reassembled the phone.
Awesome work, easier as my idea, if you have access to a heating plate. Also I like the idea with the aluminium foil, that function as a heat spreader and prevent damage or shifting or overheating of smt components on the pcb.
I got a core module with the same behavior for cheap. I will give your solution a try.
What kind of heating plate did you use?
After three weeks of daily use (and daily transport in my pockets) my phone’s screen refused to work (not even the backlight turned on when I pressed the power button). I repeated the procedure described above and now it’s back to normal again.
It’s possible that my FP2 experienced particularly much strain in my pocket today. I’ll try to transport it more in my backpack. Also, this incident underlines that the heat treatment might not be a very long term solution (however, still better than the cardboard technique).
Thanks a lot!!
I had the same problem and the pressing trick as you described worked! I hope it will last, I tried with others parts from my mother’s Fairphone and it wasn’t very helpful. I thought I had to buy a new one. Seems I don’t now
Update from my side: display worked okay-ish with the paper, but got slightly worse…
Today I removed the back cover and the visual display was super stable! Unless I pressed above the rear speaker (on the pogo pins sticking out there), everything was perfect. Putting back the cover made the phone very sensitive to touches again.
Can anyone else confirm that the back case/cover is actually causing stresses on the core module, which cause the error? Is your display also very stable without the back case?
I have the same issue. I tried with another screen and it is working fins, so I guess it is just the screen that has a problem. But before replacing it, I want to try to repair it.
I notice on the screen that 2 squares of the connector are brownish. I try to clean them, but I start wondering if it is dirty or damaged. Any idea of what I can do? I thought of welding a bit of tin on them, but if electricity is already not going through, I don’t think it will change anything…
Just my personal reasoning:
I would not do that, as the connectors then are no longer a flat surface.
Instead the ones with tin on them are standing out and might cause the other connectors to loose contact; instead of 2 bad contacts you then would have 28 of them.
My idea would be to apply some “brute force” by scratching the contacts with a brass brush or a screwdriver until they are “clean” i.e. shiny and promising to be conductive again.
I have had this kind of corrosion with battery-contactpoints quite regularly and scratching always helped.
As there are two corroded points here as well, maybe that’s were the energy flows?
Indeed, I put it here, maybe wrongly, because it is exactly the same result : screen with random colors. If someone has this problem and nothing from above is working, maybe it is just the same problem as me. But I should maybe have created another thread.
I am interested! Meanwhile I will try to fix this one and I will buy a FP3 I think…
I was not sure if it was some corrosion or some metal missing after opening/closing the FP2 hundreds of time. I will definitely try harder to scratch these point!
Excellent suggestion, I will try to find the scheme of this to understand what is going through these 2 points.
Thanks a lot!
Edit : I try to scratch the 2 pins, it looks like even worst. I a pretty sure that it is “gold” that was removed and not just a bit of corrosion. And I just bought a FP3, it is massive and heavy but looks great I will continue trying to fix this screen and open a dedicated post if I succeed.
Darn and sorry for my possibly destructive advice . Maybe in this case there is simply not enough metal / material to allow for scratching?
If just the gold is gone and it’s silver metal, the contact migh still work. Well, battery contacts are not gold-plated usually.