Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

[Jimmer777]

Hi Folks,

I picked up this LCD TV for free looking to get myself back in to working on electronics. When I picked it up I immediately noticed that one of the HDMI connectors were broken right off the board. At that time, the TV wouldn't turn on at all. I disconnected the main board to see if the backlight would come on and it did. I visually inspected the power supply board and I can't see any visual signs of cap failures. I have yet to do any testing with a multimeter.

I picked up another main board, not exactly the same but listed as a replacement on shopjimmy. Plugged it in and the TV immediately came back to life. But, after 5 minutes or so, it turned off by itself. Now the TV will only stay on for about a couple of seconds. I'm suspicious that there is also something wrong with the power supply board. Does anyone think it might need a software update / change? Not sure how I would accomplish this as the TV cuts out right away before I can get in to the menus.

Here is what I'm working with:

Main board: BN96-19438A sticker (BN41-01436C marked on the board)
Power Supply Board: BN44-00341B

Looking for suggestions on what to try folks. Thank you!

[budm]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

You need test the Voltages on the power supply connector that goes to the main board when the TV is working and when it goes into shutdown so you see what are missing when it is not working, that will be a starting point.
BN44-00341B is also know for bad PFC circuit and bad DC blocker/coupling cap in the Inverter circuit.
BTW, when you indicate that the TV will turn it self, is it like some one turn the TV POWER OFF, or you still get sound? How about the power indicator light?
BTW, your picture for the back side is cut off, I believe your TV also has the Balancer board.

[nomoresonys]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

Seems like if you get nothing from 1st mainboard then 5 minutes from replacement, you may have gotten a bad board or maybe it was damaged in shipping, did you get it from shopjimmy? they're pretty good about sending out another if so.

[Jimmer777]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

You need test the Voltages on the power supply connector that goes to the main board when the TV is working and when it goes into shutdown so you see what are missing when it is not working, that will be a starting point.
BN44-00341B is also know for bad PFC circuit and bad DC blocker/coupling cap in the Inverter circuit.
BTW, when you indicate that the TV will turn it self, is it like some one turn the TV POWER OFF, or you still get sound? How about the power indicator light?
BTW, your picture for the back side is cut off, I believe your TV also has the Balancer board.

Thanks Bud. I'm new to this forum but I've read ALOT of your posts to help bring myself up to speed here.

I think I grabbed a schematic for the power supply board, so I'll have to look in to troubleshooting the PFC circuit.

My week is pretty busy with "work" so I'll try to take some measurements this week on the power supply connector and post my findings.

When the TV "powers off", it is almost like the Power OFF button on the remote is pushed, aside from the fact you don't get the chime that it is powering down. There is no sound and the red standby light comes on.

I'll get some better pics of the back of the set tomorrow when I have some good light in the house.

[budm]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

Lets find out first as to what you have and do not have at the connector when TV is working and not working.
You should also disconnect the cable between power supply and main board and then check the PFC Voltage on the main filter cap.

[Jimmer777]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

I disconnected the cable between the power supply and main board and checked the voltages across the caps and they both measure 386V.

Here are the voltage measurements at CN802:

Pin Label TV Off (Volts) TV On (Volts)
1 B13V 0 12.89
2 LAMP_DET 0 5.14
3 B13V 0 12.89
4 SW_INV 0 5.08
5 B13V 0 12.89
6 PWM_DIM 0 2.05 - 5.1
7 GND 0 0
8 H_SYNC 0 1.66
9 GND 0 0
10 GND 0 0
11 B5V 0 5.13
12 GND 0 0
13 B5V 0 5.14
14 B5V 0 5.13
15 18VS 0 12.89
16 A5V 5.18 5.16
17 13/18VS 0 12.9
18 POW_ON/OFF 0 0.89

The formatting doesn't C&P well from Excel so I will post the results as a JPG.

[Jimmer777]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

Here is a more complete picture of the back of the TV.

[Jimmer777]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

Seems like if you get nothing from 1st mainboard then 5 minutes from replacement, you may have gotten a bad board or maybe it was damaged in shipping, did you get it from shopjimmy? they're pretty good about sending out another if so.

I'm beginning to think you nailed it. I did not get if off shopjimmy as they were sold out on any variant of the board. I did buy it from a seller that provided 30-day returns. But, for the cost of shipping its probably not worth it.

[nomoresonys]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

It looks like there's a sticker missing from your mainboard, thinking it would start with BN94xxx for identifying the board, this isn't your mainboard but example here: https://www.shopjimmy.com/samsung-bn...c630k1fxza.htm

[nomoresonys]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

Is that sticker on your original mainboard or is the picture you have there the replacement mainboard?

[Jimmer777]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

Is that sticker on your original mainboard or is the picture you have there the replacement mainboard?

Strangely enough, the replacement board has two stickers. One says BN97-05155C on one sticker and BN96-19438A on another sticker. The board is labeled BN41-01436C.

The original just had the one sticker with BN97-04040E with the similar board number, BN41-01436B.

I can't even get this TV to power up anymore. No melody or anything.

[budm]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

I disconnected the cable between the power supply and main board and checked the voltages across the caps and they both measure 386V.

Here are the voltage measurements at CN802:

Pin Label TV Off (Volts) TV On (Volts)
1 B13V 0 12.89
2 LAMP_DET 0 5.14
3 B13V 0 12.89
4 SW_INV 0 5.08
5 B13V 0 12.89
6 PWM_DIM 0 2.05 - 5.1
7 GND 0 0
8 H_SYNC 0 1.66
9 GND 0 0
10 GND 0 0
11 B5V 0 5.13
12 GND 0 0
13 B5V 0 5.14
14 B5V 0 5.13
15 18VS 0 12.89
16 A5V 5.18 5.16
17 13/18VS 0 12.9
18 POW_ON/OFF 0 0.89

The formatting doesn't C&P well from Excel so I will post the results as a JPG.

When you say TV is OFF , is that when it goes off after 5 minutes?

[Jimmer777]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

When you say TV is OFF , is that when it goes off after 5 minutes?

No, prior to hitting the power button on the remote so the TV is I guess essentially in standby mode.

From my last update, the TV won't even chime that it is turning on anymore nor do I see the backlight turning on. I did check that the backlight still powers up with the main board disconnected from the power supply this morning and it did.

The red status light comes on upon plugging in to AC mains. When the power button on the remote is pushed, the light flashes 4-5 times, goes off for about 15 seconds and comes back on solid.

[nomoresonys]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

Ok, I think I found the right board, sold out on shopjimmy but notice all the substitutes, if you can find one it should work if mainboard is problem: https://www.shopjimmy.com/samsung-bn...c610n1fxza.htm

[budm]

Re: Samsung LN46C610N1FXZC - Turns on, then off within in a few seconds

No, prior to hitting the power button on the remote so the TV is I guess essentially in standby mode.

From my last update, the TV won't even chime that it is turning on anymore nor do I see the backlight turning on. I did check that the backlight still powers up with the main board disconnected from the power supply this morning and it did.

The red status light comes on upon plugging in to AC mains. When the power button on the remote is pushed, the light flashes 4-5 times, goes off for about 15 seconds and comes back on solid.

I see.