Picade 8" screen flicker from start up

Hi Guys,

I need a bit of help as I am at my wit’s end.

Just got a Picade 8" screen and set it up last night, fresh raspberry pi 4 8Gb and a new 64Gb sd with retropie on it, I even went with a fanshim for cooling.

Tried to start it up this morning and got the “No Signal” as is usual so added “hdmi_forse_hotplug=1”.

Now the screen gets a signal, but the actual display will only show for a split second before goes back to a blank screen. I don’t mean the screen powers off or “No Signal” gets displayed, as the backlight is still on, it just goes blank, then after a random period will flash up again then disappear. I can see that the raspberry pi is working from this as between flashes I get:

a flash of boot up
A flash of a red screen
a flash of retro pie logo
a flash of emulation station boot up
and a flash of a blue screen with a grey box.

I don’t get all of these every time as the flashes are not at the same frequency each time.

I have tried every number of config.txt changes from “hdmi_group” and “hdmi_mode”, “hdmi_drive” boosting HDMI signal, disabling overscan and HDMI safe mode.

I have reseated the ribbon cable on the video driver to make sure was aligned, I have even removed the fan shim in case that was it, reseated the XHat and tried every connection, I have also tried two separate micro HDMI to HDMI cables in case something funny was going on.

The last thing I can really think of is checking with my tv to see if the pi will display on that and using a Bluray player on the screen to see if that will work without flicker.

I have searched the board here and other places for this issue but to no avail so I was hoping someone here or Pimaroni staff would be able to advise further.

Any help or advice at this point would be grateful.

Bit of an update tried using a pi on TV with and without xhat on (at this point I’m trying anything) and while TV knows it’s a pi, there is no display… So I think I may have damaged HDMI 0 when putting the machine together, I will try HDMI. 1 in a bit and update… But does anyone know if anything special is needed in config.txt to run only one screen from there?

another update on this, to narrow down suspects (whether it’s me setting up PICADE incorrectly or not) tried to use the Picade screen with my Nintendo switch, with a separate power supply on the screen to take pi out of the equation altogether.

and it works! switch shows up, no lag, no stuttery images, no fuzziness!.

So Picade I built correctly, huzzah! that is one possible problem taken out of it.

Its either a setting on my pi in “config.txt” not putting the pi display through correctly or my raspberry pi 4 mini-HDMI is borked as will not display on my TV whatsoever, not even flashing up, it does display the name of the Pi (first was “raspberry”, now it’s “Recallbox” as tried to reflash the sd card with the new OS).

while looking up solutions to this I’ve noticed that during “the flicker” the red screen is apparently a big no-no, even though I do see during the flicker that the boot is going successfully.

Is there ANYONE, that knows about Raspberry PI 4 that can help troubleshoot this with me? I am losing my mind over this

It seems like you’ve narrowed it down to the Pi not showing an image correctly, and it looks like it’s never shown one, even with the latest Raspberry Pi OS using the TV and with no HATs or fans or anything?

If you’ve definitely tried that (at least twice to make sure the sd card burned OK and with 2 different SD card) then I’d take some photos of the RPi, especially the HDMI area and send them to customer support for where you bought the RPi, and say the problem you’ve been having and the steps you’ve taken to narrow it down. If there’s no obvious damage to the HDMI port, then it may just be you have a very rare Pi with a HDMI port that’s a bit meh, and should be no problem to replace usually :-)

Hope that gives you a path to a happy place and a couple of things to double check.

Hey guru, yeah I removed the pi completely and tried it bare bones with 3 different cards, three different OS via pi imager (retropie, recallbox and raspbian) and tried on mine and a friend’s tv. I even rush ordered MORE HDMI cables to to be safe… No joy

I messaged the seller for the pi and straight away they said to send it back so seems like it’s a fault with the pi itself, I’ll update the thread when I get a new one if it works