Unsettling blue lines on screen

Greetings from Noobland. First build, using a Raspberry PI 3B+ and an SD card I bought on the internet claiming to have NOOBS preinstalled. Sadly on bootup I get these unsettling blue lines on the screen, and no response to keyboard input.

Of course I’ve read suggestions to edit /boot/config.txt. But when I look at the SD on my laptop, I don’t see that file. It makes me wonder if the SD card has the right files… is it possible the card needs new files and/or formatting?

FWIW I’m missing the ribbon cable that connects display driver to keypad… could that be the issue? (Someone told me it’s not strictly necessary, maybe they were just kidding.)

Also, the power button seems to turn the system on, but it doesn’t seem to turn the system off… I know that sounds ridiculous but that’s what I’m seeing.

Any suggestions/hints much appreciated!


Connections look good. Have you tried a different HDMI cable? Does anything normal ever appear through the blue fuzz?

Re config.txt- that won’t appear on a NOOBS card. That only appears once raspbian is flashed to the card. To that end- it may be worth manually flashing raspbian/retropie to the card using BalenaEtcher.

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Maybe this will help

config.txt is in a different location when you install via NOOBS. IMHO you would be better off ditching Noobs and go with a clean install of Retropi.

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I do believe you are the second person to report that cable missing. Go to the main Shop page, and down at the bottom there is a contact us link. You can e-mail Pimoroni tech support directly and report it to them. I would also put a link to this thread in that e-mail. I would think they would then send you a replacement.

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Actually, I’m the same one who reported missing cable–I just started a new thread with a new subject line. Thanks, tho.

Ok, I was to lazy to search to see who reported it missing. ops.

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To test the screen you could connect something else to it - laptop, set top box, etc.

I have the 10" screen, and it works perfectly without the keypad attached to the display driver board. I assume it would be the same for your 8" screen, but I can’t be sure.

Re the power switch, the fact that it turns the system on suggests the wiring is OK. The power off system runs a shutdown script (you see it run on the screen), so this could be a software issue, so I also recommend a clean install of Retropie.

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Thanks for your helpful ideas. I installed retropie on the SD. (To be fair, I’m not sure my install actually deleted the NOOBs stuff, so it may still live on the SD.) Uncommented the line hdmi_force_hotplug=1 in config.txt. Same problem on boot-- a bunch of blue lines on the display.

So I connected the PiHat to an external monitor and lo and behold! Retropie boots. We’re making progress!

So far I have not been able to get Retropie to recognize the joystick or buttons on the Picade. However, it does respond to the USB keyboard I’ve connected.

So my problem now is:

  1. getting the Picade display to work and
  2. getting Retropie to “see” the buttons and joystick

As always, thanks in advance for any insights or suggestions.

It works with an external monitor, so the Pi is good. That leaves the the HDMI cable; the display driver board; the screen ribbon cable; or the screen itself. Did you try to connect something else to the screen?

For the 2nd problem, did you install the Picade X HAT software on the Pi? To test it quit ES to go to the command line, then try the arcade buttons & joystick to see if you get anything on the screen. Just be aware that some of the buttons emulate the Esc, Ctrl & Shift keys so you won’t see anything on screen for them.

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Ah, forgot to install X Hat! Now done. Sadly not seeing anything on the command line when I fiddle with buttons and joystick. Same in emulationstation,

Tomorrow I will hunt down a suitable source/cable and see if I can get something to appear on the screen.

Thanks for your ideas!


Did the Picade X HAT software install successfully?

If it did, in the boot/config.txt file there should be the following line near the end of the file:


Also, in the boot/overlays folder there should be a “picade.dtbo” file.

I powered up the Picade and I plugged the HDMI cable from my son’s Nintendo Switch into the Picade display driver. Nothing but aforesaid blue lines.

Using external monitor, I checked yr suggestion about XHat software. I do NOT see the dtoverlay=picade line in boot/config.txt. However, I DO see the picade.dtbo file in boot/overlays.

I noticed that there’s a way to boost the signal to the HDMI in that config.txt, so I’ll try that. And perhaps set the dtoverlay line myself.

Any more insights much appreciated!

UPDATE: I inserted dtoverlay=picade line in boot/config.txt and rebooted. now the linux system seems to be reading the joystick and buttons as input (yay!). So I am feeling reasonably optimistic about getting the software to work eventually. But not so optimistic about the display :(

Sounds like the display driver may be no good. I would email support@pimoroni.com with your order number and the photos from this thread, hopefully they may sort out a replacement for you.

You’re probably right. Just out of curiosity, how do you know it’s the display driver board vs the screen itself? Since I’m in the USA, I’d hate to request a new driver, only to find that the fault lies with the screen. Dunno the relative cost or failure rate of these components. Thanks as always for any insights and suggestions, I’m really impressed with this community.

Hard to tell without spares of each. I believe they’re normally replaced as one thing though- boards screen and cables. Don’t quote me on that.

Just following up. Pimoroni shipped me a replacement screen and board at no cost. Over Xmas break my son and I installed it and got the hardware working (yes, we had plugged the joystick cable in the wrong way around).

I couldn’t get software to work properly so I reinstalled a fresh image and took the following steps:

  • uncommented the HDMI force line in boot/config.txt
  • set the keyboard to be US
  • localized the system to US
  • got wifi working
  • installed PiHat driver
  • obtained MAME romset
  • installed romset in appropriate directory

And now… IT WORKS! We’re thrilled. Thanks for all your help.