Have TV Questions? Ask a TV Technician
Hi, I'm Carl and welcome to Just Answer. I own a Repair Store and love helping people here when I get a little free time. I fix on average about 10 TVs a week and have seen just about everything. If you have no standby light at all then the Power Supply Board is most likely not producing the 5VDC Standby Voltage. An easy way to test this is to remove the back cover and while using a volt meter, place the Black Probe on the metallic frame then apply the Red Probe to the Standby 5VDC Pin on the Connector. If the power cable is plugged into the wall, it should always have 5 Volts DC. If not, replacing the Power Supply board will resolve this issue.
Let me know if you need any clarification or have any additional questions with this. :)