Without images or no knowledge of meter readings, I would say you fried your electronics or blown a capacitor. check the indicators on the fuses and capacitors. But its likely you have to replace the electronics completely.
For one, buying super cheap kits like folgertech will cost you more than it is worth, I had my troubles with retailers like them sourcing Chinese DOA arduino megas and poorly made ramps 1.4. Also chinese knockoff e3ds are not worth a damn. You better replace your electronics with the legitimate/known quality boards and drivers. I myself bought and fried 3 cheap arduino mega’s with just my USB power because the chip that manages the usb power got fried. I had 1 DOA ramps 1.4 with malfunctioning polyfuse. Also the power supply provided, put out less voltage than it was rated for, it was unable to maintain or reach temperature in the hotend.
It cost me $300+ to replace the hotend, electronics (3 Cheap arduino Megas + 1 Ramps 1.4 + 5 pololu drivers + 1 power supply + 1 Arduino Mega (Legit ones)
My advice would be to get the legit ones and save yourself months of headache.
