Testing power supply for Samsung UN40H5203 TV

Start by testing the power supply voltages on the connector going to the main to be sure they're ok and I think they will be, if so replace the main

replace your power supply filter capacitors

To find out what is going on your going to need to measure the power supply voltages and PSON voltage, start with the 5 volt supply if that is normal then test the PSON voltage it should either be 3 to 5 volt and go to about 1 volt or be close to 1 volt and go to 3 to 5 when you push the power button, if you see that change then test the other voltages. if they are all ok the power board is working ok, Be very careful around the power supply, if your not familiar with testing high DC voltage then take it in and have it repaired as the hot side voltage gets close to 400 volts on some sets.

It sounds very much like your back light bulb itself is defective or the board that connects the light to the power board.

If you don't know what you're doing, don't open it up to fix it!
There are HAZARDOUS voltages on the power supply board EVEN WITH THE TV UNPLUGGED!!! The capacitors can hold a charge for several weeks!

Clicking noise can be coming from bad capacitors on the power supply board.



It's usually easier to just replace the power supply board.

There is explained fix

https://youtu.be/wEWzYLaKdgU
https://youtu.be/02Re-UmG9Gc

Hi Hubert,
this TV uses the standard 2 pin figure 8 power cord, see image here:
Samsung power supply for UN39H5204 UN40H5003 UN40H5201 UN40H5203 BN44...

Tony, need some info for help like model number, age of set, can u unplug for 10 min. then turn back on, and since u have taken back off what have u tested or looked at?

With the Samsung PPM42S3QX Power Supply Board is the likely the cause. Testing and diagnosing - Remove the back of the TV and check the voltages on the power supply. The output voltages will be labeled on the board. Look for obvious need for replacement such as swollen caps, bad fuse, burnt components.