What are these three little transparent lines on the left and the one on the right side?

[rplex]

Hi, I got my FP4 new and looked for a way to activate the notification LEDs, that I assumed to have discovered on the outer sides of the case.
Now I had to learn that - whatever these “lights” are - there is nothing like notification LED support. But what in all the world are these things? LED mockups?

I searched all reviews up and down, but no hint…

Thanks! Uwe

[KurtF]

(Wild guess:) Just decoration…
I haven’t heard of them having any active use.

[Incanus]

Can you show us a picture of what do you mean exactly?

Do you mean these ‘lines’ at the side of the housing?

[rplex]

[rplex]

exactely… on the other side there are TWO, I just discovered a second one on the lower part

[Incanus]

I guess they are just decoration, as KurtF already said.
The FP4 has no notification LED(s).

[askaaron]

No, these lines are not “decoration” but required to help wireless signals to pass through the metal frame.

[rplex]

Really? The whole back is plastic? But it sounds more reasonable then decoration

[Lars_Hennig]

No, other phones like for example my old LG V30 have the same EM permeable plastic parts in the metal frame. This is only functional to have a 360 view to cell antennas for a better connectivity to the mobile network and/or wifi APs or possibly BT devices

[askaaron]

@rplex

Really? The whole back is plastic? But it sounds more reasonable then decoration

The back is not only plastic but also contains the NFC antenna under the black cover. There are two pogo pins to connect that with the core module:

(Source: Fairphone 4 Rückabdeckung tauschen - iFixit Reparaturanleitung)

Other smartphones with metal frames have this as well - e.g. devices freom Xiaomi and Apple.

[rplex]

Thanks a lot for replying. Yet it’s really sad I “lost” my notification LED