Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

[MadeJust]

Hey there forum,

I'm hoping to get some guidance with this. I picked up this Samsung 46EH5300 LED LCD tv yesterday. The person said it shut off one day and wouldn't turn back on.

I got it home, plugged it in, the red LED blinks once then stays solid, blinks once, solid, etc. There's no clicking.

I've opened it up and had a quick look. The caps appear ok. This is the furthest I can get without some help. What are some steps I can take now to diagnose what the issue is?

From what I've read in some other threads, it could be the main board. Is there a way to confirm this before I spend the money on a replacement board? Also, if I do need to replace the board, what model numbers need to be exact? There are two stickers on the main board:

BN97-06298N 0360 07/24/2012

BN94-06880A 8603(P03) 07/26/2012
46EH5300FX589A

Any help is appreciated.

[dick_barton]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Have you any photo's of the circuit boards and have you taken any voltage readings from the connectors.

[MadeJust]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Have photos, just uploading now.. Will edit OP.

I'm not sure which connections to test. I wanted to ask here before I poked and prodded in the wrong place.

[dick_barton]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

If you post sharp photo's showing the connections on the power supply showing the printed legends alongside would be a good starting point.

[MadeJust]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Are those ok, or should i try to get closer?

[dick_barton]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

You have 3 white connector. One on the left and two on top as shown in the photo. The only problem is I cannot zoom in to read the legends in the boxes printed on the board.
Can you measure the voltages present on those connectors and post them with
Pin number, legend associated with it and the actual measured voltage.

[MadeJust]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Here are close ups of the two connectors/legends

[dick_barton]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

I cannot see anything marked up as Standby so it will be interesting to see what voltage readings you get on CNM803

[MadeJust]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Do I need to take the board out to test these points?

[dick_barton]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

No. If you start with the board in and test CNM803 and the results will say what do do next.

[MadeJust]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Please forgive my ignorance, but how do I test CNM803? I don't see markings that indicate where to put the DMM probes.

[MadeJust]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Sorry, just realized it's the connector we're looking at. I'll test them now and post the results.

[dick_barton]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Put the black probe on the chassis and the red probe to the connections.
One side of the connector is visible and should not be a problem. If your red probe is not fine enough to push into the connector then you can use a fine piece of wire such as a leg of a capacitor or resistor and push that in and you can then put your red probe on that.

[MadeJust]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Thank you.

Pin 1 - 12.7v
Pin 3 - 12.7v
Pin 5 - 12.7v
Pin 7 - 12.7v
Pin 11 - 5.3v
Pin 13 - 5.2v

[dick_barton]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Now the other row 2 - 14

[MadeJust]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Pin 2 - 3.4v then drops/fluctuates
Pin 4 - 12.5v then drops/fluctuates
Pin 6 - 2.9v then drops/fluctuates
Pin 8 - 0v
Pin 12 - 5.3v
Pin 14 - 0.8v

I think my DMM might be junk. My other one needs a battery.

[dick_barton]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

How are you measuring the 2nd row because the 12.5V was not fluctuating when you gave the other readings. You just use the leg of the resistor/capacitor and cut it off and use it like a needle.

[MadeJust]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

I'm just making contact with the legs inside the connector. Maybe it's not making proper contact. I'll try again with a piece of wire.

[MadeJust]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Tried again, same thing... I get the reading, it drops to zero, then back up to the original reading, then back to zero. The other ones are steady readings.

It's because I have the cable disconnected. If I plug it back in, I get steady readings from 1-13 again, but I can't see anywhere to probe 2-14 without disconnecting the cable.

[dick_barton]

Re: Samsung 46EH5300 - Red LED blinks at single intervals, won't turn on

Pin 4 is the same supply as Pins 1 and 3 which you reported as steady 12.7V!!!


Pin 1 B13V, 12,7V
Pin 2 PWM_DIM 3.4V fluctuating
Pin 3 B13V, 12.7V
Pin 4 B13V,12.7V fluctuating
Pin 5 Vamp, 12.7V
Pin 6 BLU_ON, 2.9V fluctuating
Pin 7 Vamp, 12.7V
Pin 8 GND, 0.0V
Pin 9 GND, 0.0V
Pin 10 GND, 0.0V
Pin 11 B5V, 5.2V
Pin 12 A5V, 5.3V
Pin 13 B5V, 5.2V
Pin 14 PS_On/Off, 0.8V


To measure 2 = 14 you push the piece of wire into the connector alongside the cable that is connected to that pin.
Or lift the board up carefully and measure the pins from underneath but with everything connected.

It's late here and bedtime calls