Samsung UN46D6900WF no picture

[viper3166]

Have a Samsung UN46D6900WF with no picture. Backlight seems to fire then powers off, you can hear a relay click on then click off when it click off the screen you can't see the blacklight from front but can see thru small holes in the back when cover is off the panel is lit slightly. If I disconnect the power cable from power supply to main board the backlight will remain on. I have replaced the main board with the same result. Power supply? Any help would be great. Thanks Steve

[viper3166]

Re: Samsung UN46D6900WF no picture

bump

[sordids999]

Re: Samsung UN46D6900WF no picture

Posting pictures of the back of your tv showing the boards with clear pictures may help you more with fixing your problem

[budm]

Re: Samsung UN46D6900WF no picture

"If I disconnect the power cable from power supply to main board the backlight will remain on."
It means the power supply and backlights circuit are fine.
We NEED good clear pictures, the P/N of the power supply board BN44-?????.
You also need to check the DCV on the power supply board connector that goes to the main board (connector put back in place) so we can see what signals are missing from the main board.
BTW, the replacement boards are guaranteed to be good working boards? The P/N on the barcode stickers matched the original bard?

[viper3166]

Re: Samsung UN46D6900WF no picture

Thank you for your replies, see attached pics. Board mounted to back of TV is now the replacement looks to be the same model and even produced in the same month/year.

[budm]

Re: Samsung UN46D6900WF no picture

OK, the power supply board is BN44-00427B.
You need to check the DCV on the connector CNM802, there is a pin listing by the jumper JP902.
You need to provide the pin name and follow by the DCV reading when the power switch is activated so we can see what is/are missing.
Pictures provided by shopjimmy.

[viper3166]

Re: Samsung UN46D6900WF no picture

here is what I have, Attached is my pin out and they match the picture from shopjimmy.
PIN:
1 - 6.5V
7 - 33.67V
9 - 38V
10 - 162V
17 - 24V
18 - 15V
19 - 24V
20 - 16.2V

If you need anything else let me know.
Thank you!

[budm]

Re: Samsung UN46D6900WF no picture

here is what I have, Attached is my pin out and they match the picture from shopjimmy.
PIN:
1 - 6.5V
7 - 33.67V
9 - 38V
10 - 162V
17 - 24V
18 - 15V
19 - 24V
20 - 16.2C

If you need anything else let me know.
Thank you!

Well,
1) there are 20 PINS on the connector.
2) Where are the pin names as requested.
3) What did you use for the GND ref. for your meter?
4) No way you can have 38V, 162V on the pins, the power supply board and the main board would have blown up big time as you can what the Voltage labels for those pins are. The meter is good?
5) Do you have the connector back in place as suggested when you made the measurement?

[viper3166]

Re: Samsung UN46D6900WF no picture

I checked my meter had low battery.
Here are the new #'s
1 - OD_LE - 3.294
2 - PWM4 - .320
3 - OD_ON - 2.376
4 - PWM3 - .320
5 - GND - 0
6 - PWM2 - .320
7 - B13V - 12.83
8 - PWM1 - .32
9 - B13V - 12.83
10 - B13V - 12.82
11 - Vamp - 12.83
12 - BLU - 4.88
13 - Vamp - 12.82
14 - GND - 0
15 - GND - 0
16 - GND - 0
17 - B5V - 5
18 - A5V - 5.29
19 - B5V - 5
20 - PS - 3.33

Using Pin 5 as ground and connector is connected.

[budm]

Re: Samsung UN46D6900WF no picture

I checked my meter had low battery.
Here are the new #'s
1 - OD_LE - 3.294
2 - PWM4 - .320
3 - OD_ON - 2.376
4 - PWM3 - .320
5 - GND - 0
6 - PWM2 - .320
7 - B13V - 12.83
8 - PWM1 - .32
9 - B13V - 12.83
10 - B13V - 12.82
11 - Vamp - 12.83
12 - BLU - 4.88
13 - Vamp - 12.82
14 - GND - 0
15 - GND - 0
16 - GND - 0
17 - B5V - 5
18 - A5V - 5.29
19 - B5V - 5
20 - PS - 3.33

Using Pin 5 as ground and connector is connected.

OK, there is no missing control signals and the Voltages are fine, since you can see the screen glow but no pictures, then the next place to test will be the 12VDC on both end of the SMD fuse on the T-CON board with ref. to GND.

[viper3166]

Re: Samsung UN46D6900WF no picture

both sides read 12.67V

[budm]

Re: Samsung UN46D6900WF no picture

Try having one ribbon cable between the T-CON and the LCD panel connected one at a time and see you will get image on the screen.
Pictures of the T-CON board?

[viper3166]

Re: Samsung UN46D6900WF no picture

With the left side disconnected same backlight lights for a second. right side disconnected Samsung logo displays then go away.

[budm]

Re: Samsung UN46D6900WF no picture

Do you mean you can actually see SAMSUNG logo display on the screen when the right side is disconnected but if both ribbons are connected you do not see the SAMSUNG logo on the screen at all, right?

[viper3166]

Re: Samsung UN46D6900WF no picture

In picture 1 of previous post half samsung logo is display on side that has ribbon cable connected other half is blank. Picture two lines displayed. see attached pics.

[budm]

Re: Samsung UN46D6900WF no picture

OK, since you are able to see the image on half the screen with only one cable connected to the LCD panel, to me that indicates bad panel. You can try new T-CON if you want.

[viper3166]

Re: Samsung UN46D6900WF no picture

Thank you for your help! Any harm in swapping the ribbon cable position on T-Con board?

[budm]

Re: Samsung UN46D6900WF no picture

Thank you for your help! Any harm in swapping the ribbon cable position on T-Con board?

Not at all, they are the same size, pin count, and style.

[viper3166]

Re: Samsung UN46D6900WF no picture

Results:
1st photo shows the connection and second shows results.
When I connect the right side T-Con(looking from the back not screen side.) to the left lcd connector the right side(looking from back) lcd displays solid white no logo.

3rd shows the connections and fourth shows results.
When I connect the left side T-Con(looking from the back not screen side.) to the right lcd connector the left side(looking from back) lcd displays solid white no logo.

[budm]

Re: Samsung UN46D6900WF no picture

"Thank you for your help! Any harm in swapping the ribbon cable position on T-Con board?"
OK, I misread your question, you are talking about the position not the two ribbon cables which the cables are the same, I thought you are trying to swap the two cables to find out if you have bad cable.
I never try swapping the POSITION because I do not know what the signal difference between the two connectors are.