Re: Samsung UE40F6270 won't come out of standby

Hi all, it has been a while but I finally found the time to pop in a replacement PSU board from eBay. And the TV works again... mostly: now I have (on all sources: TV, HDMI, YouTube...) some dimmed (not off, dimmed) backlight in a horizontal row at the top of the screen (about the top quarter). This happens at all backlight settings (0-20, I typically have it at 10-12).

Does anyone have a clue what that might be?

Re: Samsung UE40F6270 won't come out of standby

Here a detailed photos of the table near the backlight connector and near the mainboard connector....

Re: Samsung UE40F6270 won't come out of standby

Update. I have resoldered transformer + components on heatsinks, no effect.
As as test I parallel installed a 13V power supply near the 13V exit toward the mainboard. The TV now comes on, power light blinks at normal pace (without extra 13V it is blinking in panic mode it seems), after about 15 seconds CLICK the TV shuts off again.

I am hesitant to open up the screen to test the LED bars. Any other suggestions besides getting a new PSU board? Thanks all.

Re: Samsung UE40F6270 won't come out of standby

Hi Davi.p, you're right, 12-8 and 13-9 I have anode/cathode wrong. If it's some bad LED or bad step up converter, why am I not getting 13V toward the main board even with LED cable disconnected? I am ready to pay $50 to get a new PSU board delivered at this point.

Re: Samsung UE40F6270 won't come out of standby

Before soldering I have done a few more measurements as suggested.

Please find attached a picture with numbers of voltage measurements taken just now.

mainboard cable unplugged, backlight plugged in

transformer
1 = 7.5 - 7.8 V
3 = 7.5 - 7.8 V
rest 0 V

diodes - anode
7 = 8.0 - 8.2
8 = 7.5 - 9.0
9 = 7.8 - 9.2
10 = 7.7 - 8.0
cathode
11 = 0 V
12 = 20-24 V
13 = 0 V
14 = 20-24 V

both...

Re: Samsung UE40F6270 won't come out of standby

Yes the backlight comes on, however it seems to flicker a bit. And there is a mild whining noise coming from near the center of the power board that seems to be in sync with the flicker.

In this state, the voltages measured on the connector to the main board are the same: 5V = 5.2V and 13V = 7.5V.

Does anyone have a schematic of the power supply board of a Samsung UE40F6270 TV, type L46ZF_DSM / BN44_00616A ?

See photo attached.

Symptom: after 3 weeks of being powered off, our 4 year old Samsung UE40F6270 died 1 day after using it again. That is: when on standby, it does not turn on; there is the relay clicking on, then off (few seconds, random interval), and the red standby light flashing.

Voltage measurements on connector to main board (left bottom corner on photo) when switching on: 5V = 5.2V; 13V = 7.5V. So I suspect there's something up with...

Re: New Members - please post your introductions here

Hi all, I am new to the forum and the concept of electronics dying of low quality capacitors. Our family Samsung F6200 TV has died and I am confident it's the power supply board. I hope to find more info here to pinpoint which capacitors need replacement. Thanks all!