Hello I am new to the forum (please be kind)
Weeks ago my TV (Westinghouse) Internal PCB's stamped (Samsung). Except the power supply is made by Haider (stamped). The TV would turn on and stay on for 20-30 minutes then shut off (screen would go black) power light would stay the same color (blue) but the screen would not come back on. I checked the output of the power supply and when the screen would go out the output(s) would drop to zero volts. Everyone seems infatuated with changing the CAPS, not seeing any abnormal CAPS I changed them all anyway. Then the TV would come on for only 5 minutes shut off, after power cycling the tv it would work again for about 30-90 seconds then black out again. I probed around and found two shorted resistors (15.8Ω 1 watt 1%) I replaced them and now I am getting a weird sound from the large transformer, prior to the change I was getting a hum from only the smaller transformer, now it seems from both. Prior to the last change I had 12V, 5v and 24 Volts now the 12 volts is 8v, 24v is 17, 5v is 5v 5V sense is zero. This is very frustrating what should I be looking for? The problem appears to have changed after replacing the resistors, but for the worst. Although I know there must be more problems I do not know how to diagnosis this power supply. Please help. thanks
Weeks ago my TV (Westinghouse) Internal PCB's stamped (Samsung). Except the power supply is made by Haider (stamped). The TV would turn on and stay on for 20-30 minutes then shut off (screen would go black) power light would stay the same color (blue) but the screen would not come back on. I checked the output of the power supply and when the screen would go out the output(s) would drop to zero volts. Everyone seems infatuated with changing the CAPS, not seeing any abnormal CAPS I changed them all anyway. Then the TV would come on for only 5 minutes shut off, after power cycling the tv it would work again for about 30-90 seconds then black out again. I probed around and found two shorted resistors (15.8Ω 1 watt 1%) I replaced them and now I am getting a weird sound from the large transformer, prior to the change I was getting a hum from only the smaller transformer, now it seems from both. Prior to the last change I had 12V, 5v and 24 Volts now the 12 volts is 8v, 24v is 17, 5v is 5v 5V sense is zero. This is very frustrating what should I be looking for? The problem appears to have changed after replacing the resistors, but for the worst. Although I know there must be more problems I do not know how to diagnosis this power supply. Please help. thanks