I have an LED TV Samsung T22B350EW (Type No.: LT22B350) which can not power on. I'm trying to fix it, to learn more about such type of circuits. A capacitor in its power supply board is blown up.
The board is:
PD23A0Q Samsung BN44-00505A 2012.03.14 Rev 1.3
Refer to this schematic (also available here):
The exploded capacitor is CM804 (221 / 1 kV).
I replaced it with a (hopefully) more robust capacitor F221K29S3NR63K7R Vishay 220pF ±10% 3kV cc, dielectric S3N, but it blew up as well.
I guess (according to the capacitor required features) that its terminals should receive a 220 V AC voltage. Is this correct?
By using a multimeter and an oscilloscope, and connecting this board to the mains, is it possible to detect which block causes this problem?
Maybe something before this capacitor should be investigated? For example, the STRW6052 is an integrated power MOSFET, which is the primary switcher, and I am not able to determine if it correctly works.
Is this switching power supply circuit a common one? Is there some documentation available about it?
Ideally, I would need to determine the expected voltages at some relevant nodes in the schematics, so that I can compare them with the measurements obtained through a multimeter.
Despite many Google searches, I was not able to find anything more detailed than the above schematics about the power supply circuit. It seems that Samsung did not make it available.