Philips TV does not turn on, power supply issues.

Thread Starter


Joined Jan 18, 2016
Hi guys,
I have got a Philips tv which does not turn on. When the AC mains is switched on the relay clicks and it turns back off in 1 second. The fuse is not blown. There is no stand by light either.
I have attached a schematic of the power supply. I couldn't find any bulged capacitors (I have checked most of them with my ESR meter as well) or any dead shorts.
However during my test procedure I had a 100W bulb in series with the power supply, there was a buzzing noise coming from IC1 which is L6563. I measured the VCC pin of the IC and it measured somewhere around 30V! (datasheet's stated max value is 22V). I tried measuring voltage at other pins and noticed that when I probed pin 1, the light bulb doesn't glow bright and the buzzing stops. I thought it could be a loose connection so I have re soldered the IC. But there is no difference at start up the buzz is still there unless I touch the pin 1 with the probe.
On start up the bulb is lit at full brightness and turns off when the relay turns off.
I am quite puzzled, I hope you guys could shed some light.
Thanks in advance.