Samsung lcd LE32R81B

[soul1988]

Hi everyone,
I have a 32 samsung lcd tv model ln32r81b and power it on it will blink 5 times red power light then the screen lightup for a second and go off.the power supply the tv has is a BN44-00191A i will post pictures of the power supply and tv.Any help will be appreciated thanks.

[budm]

Re: Samsung lcd LE32R81B

Here is the SCH of the BN44-00191A: just fill in the boxes
http://www.tgohome.com/ServiceManuals/

Check the PWR_ON/OFF pin, it should have >3V when the TV is turn on
Same for BL_ON pin.

[soul1988]

Re: Samsung lcd LE32R81B

I checked the voltages on the connector that is marked in the image, not sure if this is the right connector to check voltages.

ON/OFF- 3.65V when I connect the power cable and 2.46V when backlight flashe.

B/L- 0.004V when I connect the power cable and 5.72V when backlight flashe.

[soul1988]

Re: Samsung lcd LE32R81B

I checked the voltages on the 24V rail for backlight and the voltage is 27V is this normal?

[budm]

Re: Samsung lcd LE32R81B

The main key is that the ON/OFF and the BL_ON still stay >3V AFTER the backlights go out? ON/OFF and the BL_ON are generated by the main board.
Check you batteries of your meter.

[soul1988]

Re: Samsung lcd LE32R81B

The ON/OFF -3.65V and the B/L-5.72, I'm not sure if I'm in the right place to test, I marked the place in the photo that I'm testing. I do not have BL_ON in the board.

[soul1988]

Re: Samsung lcd LE32R81B

I tested all capacitors on the board, all are within the expected values and low esr

[soul1988]

Re: Samsung lcd LE32R81B

Problem solved, it was the inverter board, a transformer was damaged.

[soul1988]

Re: Samsung lcd LE32R81B

Once again is broken, this time i read 30V on the voltage for the inverter board and should be 24V, the measurement was made with the inverter board disconnected. This means that the problem this time is in powerboard right?

[tom66]

Re: Samsung lcd LE32R81B

Check and replace your multimeter battery. A low battery can lead to erroneously high readings.

[soul1988]

Re: Samsung lcd LE32R81B

battery is ok.

[tom66]

Re: Samsung lcd LE32R81B

What voltage does the 5V standby measure?