LED LCD TV screen backlight problems are getting increasingly common. LED TV Backlight Tester. This LED Lamp LED TV Backlight Tester can find defective LED on the strip in few seconds because of automatically adjust the voltage level and current. Input Voltage: 100-265V Output Voltage: 0-300V Main Application: 1. Plug in power, it would be cost about 3 to 5 seconds to start 2. The soft start mode make the backlight getting brighter gradually 3. If you can't make sure which is"+"and "-", then not test for a long time 4. Don't touch the output terminal of probes for a long time 5. Retardancy materials: Double Isolate Design makes tester safety with high strength and flame