Samsung UN55H6300AFXZA TV - Smart TV Logo, then black screen

[ECNiz]

I have a Samsung UN55H6300AFXZA TV. It was working great until it stopped working a day after a power outage. Our neighbor had to replace their satellite receiver box, so I'm assuming there was a surge in the lines before or after the outage.

The TV would not power on, the standby light would just blink when I tried to turn it on with the remote. I purchased a replacement main board on eBay. With the new main board installed, the TV will now power up and show the SmartTV logo before going to a black screen. It seems like an improvement. I'm not sure what to do now though. I've tried Mute-8-1-2-Power, and get the same thing. I've also tried Exit (12 sec) - Left - Enter.

The part number on both original and replacement main boards is B94-07774Q.

The original board has "PC05" on the sticker and the replacement board has "PC01".

Does anyone have any ideas of what I could try next?

Thanks!

[CapLeaker]

Re: Samsung UN55H6300AFXZA TV - Smart TV Logo, then black screen

check the tcon. maybe unplug one side off the panel from the tcon, turn the tv on, see what happens, then the same thing on the other side. It may be that the tcon is bad too.

[nomoresonys]

Re: Samsung UN55H6300AFXZA TV - Smart TV Logo, then black screen

And see if you have about 12 volts on each side of the tcon fuse if you have a multimeter and want to troubleshoot, as always BE VERY CAREFUL when working with the powerboard, there are DEADLY voltages on the hot side.

[ECNiz]

Re: Samsung UN55H6300AFXZA TV - Smart TV Logo, then black screen

check the tcon. maybe unplug one side off the panel from the tcon, turn the tv on, see what happens, then the same thing on the other side. It may be that the tcon is bad too.

I'll take a look. Would it still show the Smart TV logo on the screen if the TCON is bad? Doesn't the fact that a picture (the logo) is showing mean the TCON is OK?

[CapLeaker]

Re: Samsung UN55H6300AFXZA TV - Smart TV Logo, then black screen

A bad ic could work for a short time, then quit. You may need to borrow a oscilloscope and test the lvds on the main board as well. Do the backlights stay on, when it is hung up?

[ECNiz]

Re: Samsung UN55H6300AFXZA TV - Smart TV Logo, then black screen

The backlights stay on for ~60 seconds after initial power on. If I disconnect either TCON cable, I get no smart tv logo, just the backlights come on. Voltage on either side of the TCON fuse is ~12.5VDC.

Any other ideas?

[CapLeaker]

Re: Samsung UN55H6300AFXZA TV - Smart TV Logo, then black screen

Does your tv has a wifi module? If it does, disconnect it and power the tv on.

[ECNiz]

Re: Samsung UN55H6300AFXZA TV - Smart TV Logo, then black screen

I tried unplugging the wifi module, no change.

[CapLeaker]

Re: Samsung UN55H6300AFXZA TV - Smart TV Logo, then black screen

Well, I guess the only thing you can do is to check the lvds on the main board with an oscilloscope. Probe the lvds pairs and flick the menu on and off all the time on the remote. Does the tv stay powered up without the tcon? Other than that, I’d say you have a bad main board. It almost sounds like a bad or corrupt flash, or bad flash IC.

[nomoresonys]

Re: Samsung UN55H6300AFXZA TV - Smart TV Logo, then black screen

So with everything hooked up do you have backlights on and just a black screen or they go out in 60 seconds?