Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

[TVTinkerer]

As the title says, I have a Samsung UN46C6400 which powers on, the LED backlight comes on, sound works, and all the touch buttons work - but there's no picture. When powered on with no input the LED lights are fairly dim, but then when you connect an active HDMI source the backlight gets much brighter and sound comes out of the speakers.

My initial instinct was a bad T-con board, so I ordered a replacement from eBay - which says it was taken from a working TV with a broken LCD. But after I swapped it out the TV still exhibits the same symptoms. I've messaged the seller to confirm if the board was truly tested to be 100% working, meaning actually got a picture on a TV with that board installed in it, and I'm waiting for a reply.

In the meantime, is it possible that it could be something else? If the main board or power supply board were bad then I don't think everything else would be working 100% like it does, would it? Or how about a bad connector cable from the main board to the t-con? Is there any chance of that? Or is the board I got from that seller probably defective also? Any way to test it? I don't see any visible issues with either one (bad capacitors, cracked solder joints, etc).

Looking for some input before trying to buy another part to fix it, since I'm already into the TV $50 before any repairs and it's probably only worth $200-$250 in working condition.

Thanks!!

[getmoresoon]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Hi, is it no pic, or an extremely washed out one?

[dskall]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Need some pictures. Do you have power to t-con?

[budm]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Do you have 12VDC at both ends of the fuse with ref. to GND?
There are also many Voltage Test points on the T-CON.
http://www.shopjimmy.com/catalogsear...ung+UN46C6400+

[TVTinkerer]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Hi, is it no pic, or an extremely washed out one?

No pic at all, but the backlight is fully on. Screen isn't cracked or damaged in any way. And sound works, menu buttons work, everything. Just no picture.

[TVTinkerer]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Need some pictures. Do you have power to t-con?

There isn't much to see in pics, just s blank screen with a backlight on. Or did you mean see pics of the boards to see if any capacitors look like they might be bad? I'd much rather repair a board than have to buy a whole new one, I've just never dealt with anything but radial electrolytic capacitors so I don't even know what to look for on the other types.

[budm]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

We need pictures of the boards and the DC Voltage reading with ref. to GND on both ends of the SDM fuse on the T-CON board.

[TVTinkerer]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

I just heard back from the eBay seller I bough the t-con board from, and he told me he buys broken TV's and parts them out on eBay, and that particular board came from a TV where the screen was shattered so he can't say with 100% certainty if it actually worked or not. So he offered me a refund and no need to send it back. I'm guess it was probably bad also, in fact maybe since the TV stopped working the owner got mad and took a baseball bat to it - hence the broken screen! LOL

So before I order another board, is there a was to test that the proper power/signal is getting to the t-con board? I looked on ShopJimmy.com and I see the boards for sale, but I didn't see anywhere that talked about how to test the signal coming from the main board.

[TVTinkerer]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Also, one odd thing is the board that was in the TV when I got it is P/N 35-D046450. However, when I looked on ShopJimmy that board shows it's for the TV model UN46C6500VF and mine is UN46C6400RF. The boards listed for my TV are either BN81-05772A or LJ94-03436D. http://www.shopjimmy.com/catalogsear...UN46C6400RFXZA

Is it possible that this TV stopped working, someone tried swapping out the t-con board with another in an attempt to fix it, but mistakenly used the wrong board and then got rid of it when it still didn't work? So it may not even have the correct board in it? Is there any way to tell what board this TV should have in it by looking at the LCD panel model number?

[budm]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

I just heard back from the eBay seller I bough the t-con board from, and he told me he buys broken TV's and parts them out on eBay, and that particular board came from a TV where the screen was shattered so he can't say with 100% certainty if it actually worked or not. So he offered me a refund and no need to send it back. I'm guess it was probably bad also, in fact maybe since the TV stopped working the owner got mad and took a baseball bat to it - hence the broken screen! LOL

So before I order another board, is there a was to test that the proper power/signal is getting to the t-con board? I looked on ShopJimmy.com and I see the boards for sale, but I didn't see anywhere that talked about how to test the signal coming from the main board.

Read post #7 again.

[TVTinkerer]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

I found my panel number which is T460FBE2-DB, and when I looked that up the only matching T-con board is P/N BN81-04456A (also called 35-D052600).

http://www.shopjimmy.com/catalogsear...&q=T460FBE2-DB

[TVTinkerer]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Read post #7 again.

I'll try to test it. And when I asked that, post #7 didn't exist yet, it was posted while i was typing.

[TVTinkerer]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Which one is the fuse that I need to test? Is it C_DF1 just above and to the left of the cable that connects to the main board?

[diif]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Which one is the fuse that I need to test?

It's white with the letter N on it. Up and left from the left hand side of the LVDS connector.

[TVTinkerer]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Finally had a chance to check the voltage, I get 27V on either side of that fuse. I assume that means the fuse is good? Anything else I should check?

[budm]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

You better check your meter and meter setting, there is NO WAY you can have 27Vdc on that T-CON fuse without the T-CON and main board blown up. It should be only 12VDC.

[TVTinkerer]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

You better check your meter and meter setting, there is NO WAY you can have 27Vdc on that T-CON fuse with out the T-CON and main board blown up. It should be only 12VDC.

I'm an idiot, I had it in AC mode! Looks like it's 12.67-12.68VDC, same reading on both sides of the fuse.

[maxvalutech]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Just a thought but how do you know menu button was working and are those t-con connectors to screen seated in far enough ?

[TVTinkerer]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

Just a thought but how do you know menu button was working and are those t-con connectors to screen seated in far enough ?

I don't necessarily know the menu button specifically works, but all the others do. I can change the source, adjust volume, power on/off, etc. The menu button would bring up a menu that I obviously wouldn't be able to see, but I just figured if most of them they probably all work.

And yes, the connectors are seated fine, I've double and triple checked that both with the original board as well as the replacement.

I did notice that while the name on the top of the new board I received is the same (V460H1-CH7), the actual model number is different (orig board 35-D046450, new board 35-D052554). But according to some resources I've looked at (such as this eBay listing which shows compatible p/n's: https://www.ebay.com/itm/142518918534) they *should* be interchangeable.

[TVTinkerer]

Re: Samsung UN46C6400 - TV powers on, backlight comes on, buttons work, but no pic.

I have until the end of today to either fix this TV or return it where I bought it (10 day return policy) if I can't get it working. So I'm pretty much at the end of my rope. Any other ideas?? Is it possible that all the boards are fine, and it's just a bad panel? Everything else seems to work - backlight, sound, buttons, the LED backlight gets brighter when I connect a source, there's just absolutely nothing on the screen.

If that replacement board I got was indeed good, and the other boards appear to be fine, then the only thing left would be the panel itself. No?