About Ultra Violet (UV) Marker Pen
One of my recent students shared about having a UV marker pen to find out which component already been replaced by the repair tech. It was a smart move by him. Whenever the circuit board have problem (industriall type of circuit board) his company have to send it back to the supplier to repair and the cost of repair was very high. What he do, he used the UV marker pen to label all the components on the circuit board. After the board had been repaired, he took out a UV detector and scanned the board. For your information we can't use our bare eyes to detect the UV marking.
He told me almost all the board that he sent were caused by only 2 bad components because that 2 components does not have UV mark on it. And the components were voltage regulator ic and an electrolytic capacitor. By using this method his company saved thousands of dollar every year. What a brilliant idea.