I've had this problem recently with Legend of Mana for psx. It was the controller type that was set to analog, but the game refused to work until I changed it back to standard and restarted it. Some cores/games are a bit finicky with analog controllers and how they're configured, in my experience. Try messing with that option to see if solves you problem.

The BIOS started the games. Thanks @mitu!

Okay, so now I'm getting blanking AND random "No Signal" to the TV. The no signal issue recovers when I exit the game. Could it be my seven dollar HDMI cable?

Thanks all for your help. I found a good image for the Pi0 and dont have any problems now :)

Image: Super RetroPie

Try gpsp's non-retroarch version. With this version, you'll probably have less lag on GBA games, since it consumes less resources than the default retroarch version.

I've tested this version on a Raspberry Pi 1 B+, and I remember playing some GBA games without lag. It was on 2015, and back then, if my memory serves, there was no lr-gpsp yet.

I don't know if it'll work on your Pi Zero, but assuming Pi Zero and Pi 1 has approximately the same hardware, there's the chance that it can work.

Thanks for the reply! I installed Retroarch on my phone to see a bit of what you mean. Fewer shaders are available and the same shaders I use on my PC look different thanks to the phone's much higher PPI, and/or maybe some other factors. I suppose this would mainly apply to people playing on Windows or Linux on a 1080 - 4k screen. If you feel this question is of no use here, feel free to remove it.

You emulators.cfg for the gba system is corrupted. It should be:

lr-mgba = "/opt/retropie/emulators/retroarch/bin/retroarch -L /opt/retropie/libretrocores/lr-mgba/mgba_libretro.so --config /opt/retropie/configs/gba/retroarch.cfg %ROM%" default = "lr-mgba"

Replace the file with the contents I pasted above and re-try.

Roms are all working on my PC.
I realize it was just a issue during the transfert of the rom to my raspberry, now it should work.... but actually my raspberry pi seems not to respond to my SD card.
I tried to reboot on the new retropie IMG, and nothing. Green led blink twice, then nothing.... when I try the same SD card on another pi It's working.

If you have any advice for this issue, that would be great.
You already helped me a lot. Thank you.

@drago-supremo The default settings - of the RetroArch included in RetroPie - is to use and preserve the apect ratio of the emulator used, scaled to the resolution of the your output.
If you still want to change it, you can use the Runcommand launch menu (https://retropie.org.uk/docs/Runcommand/#runcommand-launch-menu) to set the resolution per core (emulator) or game.

Thank you so much for all your help I just changed the emulator it used and got a new rom and it worked.

So a bit of an update. Since I was no longer using my RPi3 (I had ordered a XU4) I decided to experiment with it (the RPi3) more than I had before and I installed Lakka on it, and it worked perfectly. Out of the box the games look amazing and the (few) that I have tried, both SNES and PS1 have run perfectly.

This tells me that there isn't a problem with the pi, the power supply or the sd card, its just something different in the versions/configuration in RetroPie. For clarity sake, I always installed RetroPie from official builds, and tried multiple times, always trying to use it with out of the box defaults first.

I gave the RPi3 away, so I can no longer test with it (the XU4 runs circles around it) but it is good to know that it was at least capable of running the emulators that I thought it wasn't.

I have not put RetroPie on the XU4 yet, I am trying to get a decent set of benchmarks (games that run smoothly in Lakka) to compare.

@shay90 gpsp needs a bios. Without it nothing will run

That’s handy to know, when I moved my lad’s system from a zero to a pi3, I had issues with saves. Thanks

@mrbear2899 either bind the hotkey to the same button as fastforward, or disable hotkeys entirely.

I would say that with today's technology yes, though it would be near impossible to do so without connecting the game cartridge to the computer :). So unless you have some sort of GBA-2-USB adapter, I would say no.

I was trying to accomplish the same thing, but couldn't find anything specific. I found a general solution, but it's a bit ugly and it would be better if lr-mgba could add a turbo button enable/disable core option (similar to fceu). I know this is an old thread but hopefully it helps someone.

Note: If you have a controller without L3 or R3 stick buttons, you can just map all the turbo functions to those buttons from the RetroArch menu and you won't need to do any of this.

Buttons can be completely disabled by changing them to "nul" in the joypad-specific files in /opt/retropie/configs/all/retroarch/autoconfig but that would affect all cores. You can make the change core-specific by making a copy of those file(s) and putting a joypad_autoconfig_dir line in your gba retroarch.cfg:

First, open the RetroArch menu while lr-mgba is running and map the turbo A and turbo B buttons to L2 and R2 (the same as turbo L and turbo R default mapping). This way you'll only need to disable those 2 buttons.

Then make a copy of your joypad configs:

cp -R /opt/retropie/configs/all/retroarch/autoconfig /opt/retropie/configs/gba/retroarch-joypads

In each of the .cfg files in the new /opt/retropie/configs/gba/retroarch-joypads directory (if you have more than one type of joypad), change these lines to disable the L2 and R2 buttons:

input_r2_btn = "nul" input_l2_btn = "nul"

Then add to /opt/retropie/configs/gba/retroarch.cfg

joypad_autoconfig_dir = "/opt/retropie/configs/gba/retroarch-joypads/"

You can comment out that line and re-map turbo A and turbo B to change back to the default behavior later. Be careful not to set any buttons you need to navigate the RetroArch menu to "nul" because it disables them there as well.