I'm a beginner and just got my Raspberry Pi 3 model B. I also ordered the Kuman 3.5" LCD TFT screen that runs off the pins with my Pi. I have the drivers for the screen that comes with a modified version of Raspbian and it runs just fine. But I actually got the screen so I can make a mobile emulation station that I can take on the go, however the screen won't work when I have Retropie with the drivers for the LCD screen. Whenever I connect directly to the Pi with my tv through HDMI it works just fine. Is there a way I can transfer the display to go to the LCD automatically?
I came across this issue a while ago, I read something about LCD's which connect to the Pi over GPIO use special kernels, and require drivers along with certain graphics processing to work, mainly relating to OpenGL.
In the end, I just purchased http://www.dx.com/p/2-ch-video-input-3-5-tft-lcd-display-monitor-module-w-cable-black-silvery-grey-ntsc-pal-201631#.V-MtXZN96Ho which uses RCA video, and works fine with retropie.
Though, have you tried enabling SPI within
raspi-config, or commenting out the line
blacklist spi-bcm2708 in
Hope this helps!