Smps (bn 44-000333a)

[Rusty Brown]

Need Help in Learning
I would like to test the board (BN 44-00333A). I have a few questions regarding reading label on connector CN801 (SMPS to Main board).
Label
15V PS-ON
15V STBY
5.3V 5.3V
5.3V RTN
RTN RTN
15V RTN
15V NC
15V NC
Question: 1 – The voltages given in the left column. Are these the voltages when the TV is in ON position and the voltages on right column, when the TV is in standby positon or it is something else?
Would you explain the followings?
PIN 3 from top: 5.3V 5.3V
PIN 8 from tip: 15V NC
Question 2: From my research, the STBY voltage is 5V. However, on (BN 44-00333A) it is 15V. Is it correct?
Question 3: Self testing SMPS
It requires the followings modifications on CN 802 (SMPS to Logic Board)
a) Use jumper cable, connect PS-ON pin with RTN pin.
b) Similarly, connect pin VS-ON with pin STBY5V. In my case STBY is 15 volts. Do I have to use pin (15 V STBY) or I have to use some other pin with 5 volts.
c) Read voltages on SMPS.
Thank you.

[R_J]

Re: Smps (bn 44-000333a)

There are two rows of pins on that connector
IE: pin 17 = 15vamp pin 18 = PS-ON
pin 15 = 15Vamp pin 16 = STBY
pin 13 = 5.3V pin 14 = 5.3v
pin 11 = 5.3v pin 12 = RTN
etc

stby would be +5 volts
NC means No Connection
RTN return or ground
If the power supply board has pull up resistors for the pS-ON then unpluging the connector to the main board would turn the power supply on. If it does'nt then with the mainboard plug disconnected, put about a 1K resistor between PS-ON and STBY +5

[budm]

Re: Smps (bn 44-000333a)

The connector CN801 has ODD Column pins which you can see and probe from the tops side of the board, the EVEN Column pins you will have to probe from the back side of the connector where the wires go in or flip the board over to get to the even pins.
The label for each pins show what their functions are.
If you look at the print you will see that
The ODD column pins are:
Pin 1, 3, 5 are 15V
Pin 7, 9 =GND return
Pin 11, 13 = 5.3V
Pin 17, 15 are for 15V amp
The EVEN Column pins are as shown on the print, I.E. Pin 18 = PS-ON
The power supply board will have Standby Voltages, Switched Voltages, the Command Voltages. So you will to learn what the Voltages are on how the board functions.

Pictures provided by Shopjimmy.

[Andrew F. Ali]

Re: Smps (bn 44-000333a)

Excellent......So with a 1Kohm resistor connected across the Pin 11: PS-On and Pin 18: 5.3V on CN801. Connect two (2) 120Vac 60Watt house light bulbs in series and connect that across Pin 1: VS and Pin 3: RTN on CN804. Then plug into ac. If the PSU is good the house light bulbs will glow bright and you can measure VA:54-56Vdc on CN804 and Pin 1:15Vdc on CN801 and Pin15:15Vdc on CN804

[Rusty Brown]

Re: Smps (bn 44-000333a)

Thank you R J, BUDM and Andrew F. Ali for you kind help.

TV: Samsung Plasma, Model PN50C7000YF

Please let me know if the following procedure is correct to test SMPS (BN 44-00333A). I want to be sure before doing any testing.

1. Disconnect all cables from the board.
2. Connect power and measure STBY (5 V) and PS-ON voltage (2.5 – 5 V) on CN 801.
3. On connector CN 801 (SMPS to Main Board) short PS-ON pin with ground. Check Va (it should be 55 volts).
Question: Can I use CN 802 (SMPS to Logic Board) for this purpose.

4. On CN 802, supply 5V to VS-ON pin. Any 5V pin (from CN801 or CN 802) can be used. Check for Vs voltage (it should be 211 volts).
If all the conditions are met, then the SMPS is good.

[budm]

Re: Smps (bn 44-000333a)

Most Samsung power supply boards for Plasma TV use ACTIVE LOW 9Ground the PS-ON pin = ON) to turn on the power supply, so run the power supply board by itself and then check the DCV on the PS-ON pin to see if it shows >2V or so and report the reading.
Found the diagram and it looks like it has pull-up resistor for the PS-ON so it looks to be ACTIVE HIGH. I did not look at the schematic in details yet.