Rock Pi 4C reboot issue

I bought the 4C with the quad sata hat. I had issues getting USB to work and have just sorted that by installing Armbian 5 buster. It booted initially to a command prompt and I used armbian-config to install a desktop and after that OMV5. Since I had issues initially I’m just running the 4C without a heatsink, haven’t set up the sata hat yet. The system ran OK until I touched the power cable and it rebooted but into a black screen. I couldn’t get it to run so re-flashed the emmc and it works OK until I move the board in any way, just reboots to black screen. Any ideas what’s wrong?