Samsung PS replacement

[anupkg1985]

Hi,

I have a Samsung led tv with bad PS however I have another good PS from different model of the Samsung tv which has similar outputs so just wanted to confirm if I can use that one Below are the links for the PS -

Bad PS -
https://www.shopjimmy.com/samsung-bn...ply-led-board/

Good PS -
https://www.shopjimmy.com/samsung-bn...ply-led-board/

Let me know if I can use bn44-00500a instead of bn44-00499a ?
anupkg1985 is online now Report Post

[nomoresonys]

Re: Samsung PS replacement

Is a good question, I see the 500A is for a 60 inch and the 499A is for a 50 inch tv, not sure if the powerboard would put out to many volts for yours or not.

[anupkg1985]

Re: Samsung PS replacement

Updated the broken urls -

Bad PS -
https://www.shopjimmy.com/samsung-bn...ply-led-board/

output ratings -

A 5.3 V 18 mA
B. 5.3 V 1.1 A
B. 12.8 V 2.1 A
Vomp 12.8 V 0.3 A

CNL. 331 V 289 mA

Good PS -
https://www.shopjimmy.com/samsung-bn...ply-led-board/

output ratings -

A 5.3 V 18 mA
B. 5.3 V 1.1 A
B. 12.8 V 2.1 A
Vomp 12.8 V 0.3 A

CNL. 224 V 260mA

Good PS is from 60" tv and I'm trying to put it in 55" tv.

[budm]

Re: Samsung PS replacement

They are not compatible, the 500 has two boost converters to drive each LED string, the 499 only has one boost converter to drive one large LED string that is why drive Voltage is 331V..and the 500 is only 224V

[R_J]

Re: Samsung PS replacement

.

[anupkg1985]

Re: Samsung PS replacement

They are not compatible, the 500 has two boost converters to drive each LED string, the 499 only has one boost converter to drive one large LED string that is why drive Voltage is 331V..and the 500 is only 224V

What if we alter the one large LED strips and make it compatible with 224V, not sure though if it's possible? By combining the pieces in parallel and series?

[budm]

Re: Samsung PS replacement

You have to know how many LED the whole string has, then you have to divide then into two set and then each string has to be able to be driven the new drive Voltage, then you also have dimming control to deal with, since it is two separated drive circuit, each circuit may be driven individually by zone control.
So bottom line, it is not that simple.
What is wrong with the power supply board? Did you verify that the LED strings are all OK?

[anupkg1985]

Re: Samsung PS replacement

Haven't checked the PS yet but will post the finding once I perform the checks on it. However I would like to know what is dimming control, does it take care of light brightness based on the picture light?

[budm]

Re: Samsung PS replacement

Dimming control is for setting the Backlights level (not the same as Brightness)).
Most of Samsung power supply/LED driver can perform self test by powering the power supply board by itself with out having the cable between and main board connected, when AC is applied to the power supply/LED driver board the backlights should come on right away and stay on as long as the AC is applied to the power supply/LED driver board.
What level of repair experience are you when dealing with TV?

[anupkg1985]

Re: Samsung PS replacement

I'm not professional, its just a hobby for me. Just seeking more knowledge on this.

[nomoresonys]

Re: Samsung PS replacement

Some on that page, some of the prices aren't really too bad for a 55: https://www.ebay.com/sch/i.html?_fro...acat=0&_sop=15

[anupkg1985]

Re: Samsung PS replacement

Here is the issue with bad power supply. I see main fuse (FP801S) is blown and one of the capacitor (CS802) is damaged. Could someone let me know what could be the issue? Is the problem with PWM controller?

[budm]

Re: Samsung PS replacement

That blue cap is the snubber cap for SMPS IC (6-pin IC mounted on the heatsink).
Remove that blown cap the check the resistance between the two pads of the removed cap, check the resistance of RS802, report the resistance readings.
That snubber cap is common failure cap, it will fail as shorts circuit.

[anupkg1985]

Re: Samsung PS replacement

RS802 measures around 0.6 Ohm not sure if thats correct as resistor has 5 bands.
After removing bad cap the resistance between two pads is 60K Ohm however after reversing probes it goes to 30+M Ohm.

[budm]

Re: Samsung PS replacement

RS802 measures around 0.6 Ohm not sure if thats correct as resistor has 5 bands.
After removing bad cap the resistance between two pads is 60K Ohm however after reversing probes it goes to 30+M Ohm.

That is good, the Source resistor is fine, and the internal power MOSFET of the SMPS IC is also OK based on the resistance reading.

Can you still read the print on that high Voltage rating ceramic cap?
You should also check the bridge rectifier to make sure it is not damaged when that cap shorted out.
Also check the resistance between the two legs of the main filter cap (100uF 450vdc) cap.

[anupkg1985]

Re: Samsung PS replacement

Bridge rectifier looks good when checked on the board itself. Ceramic cap reads as 68K 1KV. The resistance between main cap is around 63K ohm and 30+M Ohm when reversed.

[budm]

Re: Samsung PS replacement

That is 68pF 1KV, I would get 2KV rating at least.

[anupkg1985]

Re: Samsung PS replacement

Sorry I'm not sure what does that means? Do you want me to replace the cap and test the circuit?

[budm]

Re: Samsung PS replacement

Since the bridge and the resistance test on the main cap are OK, all you have to do now is to replace that snubber cap, then you can try powering up the board by putting 75W 120VAC incandescent lamp in place of the fuse, if the lamp comes on bright and stay bright then you have more problem on the board..

[budm]

Re: Samsung PS replacement

Sorry I'm not sure what does that means? Do you want me to replace the cap and test the circuit?

That s the cap rating.