The DC power jack to the board is clearly marked 5V DC. By applying +10V you have almost for certain damaged of blown away every IC on the board. That would appear to include the 24C02 serial EEPROM, the RS232 level translator chip, the IR receiver chip and the main AT89S52 MCU. If the LCD1602 was attached that is also most likely fried too. I would not trust any component that went through that treatment.

I'd say time to buy something else. This time make sure you focus on something that comes with proper documentation - at least a decent schematic.

Michael Karas