Flashing screen when using Carplay

I’ve just randomly got a blinking screen on my Pi 4b. The screen turns of for like 2 seconds and then it turns on and it keeps doing this. Mostly it’s doing this when it searches for the carplay connection. Once the loading screen comes up the screen goes black for 2 seconds and when the screen comes back it stopped searching for the carplay connection. It seems like this issue is only happening when i have the carplay dongle connected. When i remove it it’s completely fine. Also when i scrolled in the directory it did the same.

When the screen goes black. And then appears again it feels like it changes the aspect ratio. Because the button in the center of the carplay program isnt centered but after a few sec it goes back to the middle.

What i tried so far.
Reinstalling Carplay.
Updating the OS.
Tried different HDMI
Tried the carplay dongle on my other Pi <---- It works
It doesnt show any warnings about low power.


Newbie here, so take my advice with caution

Sounds like an issue I had where the pi is trying to power too many devices.

There is a limit to what you can plug in to power from the pi, I now have an externally powered usb hub which I put everything into.

It can’t be. Since i’ve removed everything execpt the usb power to the display.

Also It has been working great for a few months. with all the usb ports taken.


It seems like it’s my main screen from Waveshare that i causing the issues when the dongle is connected.
I’ve now tested it on both my TV and PC monitor and on those it’s working without issues.

But why does the problem go away when the dongle is not connected on the Waveshare screen???
Like after the screen comes back it looks like the screen aspect ratio is changing.

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Turns out it was my CarPlay dongle that was faulty. Got a new one and it now works.

The dongle was problebly faulty from factory since it always had poor network connection and it problebly was just dying the more i used it xD

Signs of it being faulty:
Starting to fail to connect and just showing a white screen to after some days later to start flashing the screen. However the CarPlay dongle still works if i connect the Pi to another screen.

Awesome, thanks for the feedback, and apologies for lack of response, things are quite manic right now!

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