⟐ Commented March 25, 2026 at 1:07 MST

⟐ Answered March 24, 2026 at 21:48 MST

⟐ Answered March 24, 2026 at 21:35 MST

When power is plugged in, the indicator light will turn on, the backlight stays off and nothing is visible, even with a flashlight. When pressing the touch buttons on the tv nothing happens. When pressing buttons on the remote control the indicator light will blink indicating the IRsignal was received, but nothing happens.

Out of the 20 times that I have booted it, it did turn on 3 times and stayed on. It then showed a ‘No Input’ screen with a perfect screen without glitches. After powering it off and on again with the power button, then it would not show a picture anymore.

Troubleshooting:

• All power supply connector voltages are normal, except there is no backlight_on voltage. Standby power is 5 v
• Return power from the main board to trigger the power supply board is 3.5v.
• Manually shorting the Backlight on with the Power supply on lights the backlight normally and will stay on as long as I short it.
• I have reseated all connectors going between the boards.
• I have checked all diodes and capacitors on the PS board. All diodes are one-way and all capacitors show acceptable ESR.
• I have tried to find out why it did boot sometimes, but have not been able to. Have tried pressing on the main chip for example.

The main board is DUNTKG135FM08. The power supply board is RDENCA459WJQZ.

Board diagrams in PDF:

https://1drv.ms/b/s!AkpE6xgs6VHNhGNwakvV...

I am guessing there is a problem with the main chip or the standby chip IC3800. I’m not sure where to go from here. Any help is appreciated.

⟐ Commented March 16, 2026 at 6:46 MST

model number LC-40E67UN

⟐ Answer edited February 05, 2026 at 8:00 MST

⟐ Answered January 04, 2026 at 16:27 MST

⟐ Commented December 22, 2025 at 10:04 MST

1- The TV powers on by itself and switches to AV input with the volume set to 30.

2- The USB port only plays audio files and photos. Video files either do not play at all or play for a fraction of a second before the TV restarts. I have tested multiple video formats and codecs without success.

3- When connecting an Xbox via HDMI, I receive audio but no video.

4- Satellite channels from my receiver work perfectly via HDMI — the receiver displays all channels and plays video normally on other displays. Also, when I plug a USB flash drive into the receiver’s USB port, video playback works fine. This suggests the issue is specific to the TV’s USB and HDMI video handling

Troubleshooting steps I have already tried:

Attempted a power reset using the TV power button, but it had no effect.

I could not find the hidden/service menu to perform a factory reset.

I tried to access the TV service menu like this: first I unplugged the TV, then I held down the power button. While still holding it, I plugged the TV back in and kept holding the button until the indicator light started blinking (it blinked only green, not red). Then I pressed the power button four more times and held it on the fourth press until the Sharp logo appeared on the screen, then I released it. According to tutorials I watched on YouTube, the service menu should have appeared at this stage, but it didn’t. I tried many times and it made no difference.

Testing multiple USB drives and formatting to FAT32.

Testing different video formats (including MP4/H.264).

Connecting a working receiver and confirming that the receiver displays satellite channels.

Requested assistance:

Please advise whether there is an official firmware update for model 40SA5200 that may resolve these issues and provide the download link and installation instructions if available.

If firmware update is not applicable or does not resolve the problems, please advise on recommended service/repair options. The symptoms suggest a possible main board or power/factory firmware fault.

TV details:

Model: AQUOS 40SA5200

⟐ Answered December 17, 2025 at 19:04 MST

1- The TV powers on by itself and switches to AV input with the volume set to 30.

2- The USB port only plays audio files and photos. Video files either do not play at all or play for a fraction of a second before the TV restarts. I have tested multiple video formats and codecs without success.

3- When connecting an Xbox via HDMI, I receive audio but no video.

4- Satellite channels from my receiver work perfectly via HDMI — the receiver displays all channels and plays video normally on other displays. Also, when I plug a USB flash drive into the receiver’s USB port, video playback works fine. This suggests the issue is specific to the TV’s USB and HDMI video handling

Troubleshooting steps I have already tried:

Attempted a power reset using the TV power button, but it had no effect.

I could not find the hidden/service menu to perform a factory reset.

I tried to access the TV service menu like this: first I unplugged the TV, then I held down the power button. While still holding it, I plugged the TV back in and kept holding the button until the indicator light started blinking (it blinked only green, not red). Then I pressed the power button four more times and held it on the fourth press until the Sharp logo appeared on the screen, then I released it. According to tutorials I watched on YouTube, the service menu should have appeared at this stage, but it didn’t. I tried many times and it made no difference.

Testing multiple USB drives and formatting to FAT32.

Testing different video formats (including MP4/H.264).

Connecting a working receiver and confirming that the receiver displays satellite channels.

TV details:

Model: AQUOS 40SA5200

⟐ Marked as duplicate December 17, 2025 at 8:05 MST

⟐ Answered December 17, 2025 at 0:33 MST

⟐ Commented December 09, 2025 at 2:56 MST

If I have my Xbox turned on, the TV will display it when powered up. But I can’t change volume or access menu etc… The remote has good batteries and the IR is working (checked through phone camera). I’m stumped! Is this a failing board? A known quirk?? Any help is greatly appreciated!

⟐ Commented November 24, 2025 at 17:36 MST

⟐ Answer accepted November 17, 2025 at 2:15 MST

I opened the TV, I checked all the board, I saw no burns on cables or anything bad. I reseated all cables to no avail.

I replaced TCon, but TV still does the same thing. Can it be a bad main board or something else like the power supply or the actual panel?

When the scene is dark, the lines kind of disappears but as soon there is white info on screen lines came back again.

Hoping you guys let me know were to start with it.

This post is my tv, with photos.

TCon replaced, Vertical lines still there. Something else?

Thanks in advance for any support!

⟐ Commented October 18, 2025 at 20:33 MST

⟐ Commented August 19, 2025 at 13:41 MST

⟐ Commented July 15, 2025 at 7:10 MST

⟐ Commented June 29, 2025 at 18:57 MST

⟐ Commented May 08, 2025 at 9:48 MST

I have owned this LCD TV since 2012. The only repair was the replacement of the PSU a few years ago. Apart from that, no issues. Recently, all was working fine until I switched on to see it appear as so. The day before it was working fine. There is sound. Could this be a T-Con board issue? If not, what could it be? Thank you.

⟐ Answered March 25, 2025 at 0:23 MST