Samsung LCD TV Power Supply BN44-00438B

[liomendonca]

Re: Samsung LCD TV Power Supply BN44-00438B

ok I have gone back and checked the PS_ON and it seems to be Ok
TV off LED ON PS_ON is 3.5v
TV on LED OFF PS_ON is 0 V
Capacitor stays at 160v with TV on or off
As long as 110 plugged in capacitor 160V
Maybe after a few hours it should discharge to zero even with 110 plugged in?
You said if PS_ON is OK then it is definitely Power Supply
Still need photos?
If you do hope my photography is up to mark
Thanks again

[budm]

Re: Samsung LCD TV Power Supply BN44-00438B

At this point you do have power supply problem due to the PFC Voltage booster is not running when PS_ON is present.
The 160V will always there as long as the TV is plugged in so the standby power supply can run.

[liomendonca]

Re: Samsung LCD TV Power Supply BN44-00438B

OK so at this stage should I order the power supply or is it likely that I can repair it with my limited knowledge A quick question. Why do guys like you spend all this time and effort to help people
Do you gain anything besides satisfaction?
If we stop here then thamks again

[budm]

Re: Samsung LCD TV Power Supply BN44-00438B

1) I like to learn and keep up with new technologies (I worked in many fields of electronics).
2) Keep the stuff off the landfill. I do my volunteer works once a week at Electronics recycle so I get to see the inside of the products and figure how it works and how they are put together. Hands on is the best thing for learning.
3) I use the knowledge of what I see and learn here and from lots of people and lots of other places to see how products are made so i can improve what I design into the products.
4) It is fun.

[liomendonca]

Re: Samsung LCD TV Power Supply BN44-00438B

OK I am now stuck as I have been bitten by the "repair" bug. In my younger days I built I think every Heathkit so now nostalgia has set in. But I must be able to find the schematic for the BN4400438B. Is the BN4400438A similar? Any schematic for that?

[liomendonca]

Re: Samsung LCD TV Power Supply BN44-00438B

Just thought of the possibility of using a separate power supply to power the backlights?