I used this Arduino Uno for a almost three years to control lights. Everything worked perfectly. Last week I wanted to revise my program and I realized that Arduino wasn't recognized by my PC ( Windows XP OS) I tried it on another PC ( Windows 7)>> same happened. SoI downloaded new package, installed on Windows 7 and everything seemed to be back in business again.
First I tested with my original sketch. I push the switch and correct light is on. But when I switch it off, it takes 4 seconds to turn OFF the light.
I testet another sketch with one servo and one button. I push the button and Servo goes immediately. I should be able to push the button again to command servo back to its initial position but it works only if I first wait for a 4 seconds.
I uploaded my sketches to Arduino UNO which I bought this year and everyhting works fine. So, it can't be programing issue.
Text on the board says: BOARD MODEL UNO OPEN SOURCE ELECTRONICS PROTOTYPING PLATFORM DESIGN IN ITALY WWW.ARDUINO.CC
Still, it could be a Chinese copy