I own a LG47LH40 TV and it suddenly changes picture from a nice vivid pix to a much darker display, then stays that way. It was an intermitted problem but this time it seems to be staying permenantly dim. I am wondering If anyone else has had a problem like this. I thank you all in advance for any help you can give me.. Its a shame to toss the TV... Id like to try and do the repair myself .... worst I can do is break a broken TV right? thanx to all JS
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Re: dim display backlight?
Is this an LED or florescent backlit display?
If it's the latter, you can start by checking the inverter transformer(s) for an open circuit high voltage winding.
Also, check for cracked solder joints. Inspect the wiring for the backlight for arcing or bad connections.
Some pictures would help us too
-BenMuh-soggy-knee -
Re: dim display backlight?
the tv is an LED I am curious if the dimming of the screen sounds like an issue w/ the backlight or could it be something else... I took just the back of the tv off and looked closley w/ a magnifing glass I see no swollen caps or burn marks anywhere... I dont have any paperwork to dissasemble it further and am wondering if there are any instructions to be found anywhere.Comment
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Re: dim display backlight?
It could be failing LED(s). It also could just be a dodgy connection. Or perhaps the LED driver is faulty.
I'm not great in the service manual area of things, however there are a few folks on here who are, they likely will chime in sometime soon.
In the mean time if you want you can upload some pictures of the circuit boards and post them on the forum here.
P.S. I just noticed, you live in the garden state as well
-BenMuh-soggy-kneeComment
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Re: dim display backlight?
Can you change the setting from VIVID to user pref mod to see if you can adjust the backlights (not brightness) level? Also does it have the auto brightness that will change with the room lights? you may try turning that function off.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: dim display backlight?
reguardless of what I adjust, it stays dim,,, even called LG, the tec. talked me back into the factory settings... still dim,,, w/ auto brightness off picture is still very dark / dim.... its not an adjustmet... I think something's going bad to make it darken like thisComment
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I have a Panasonic LED TV TC-40A420U. The TV was given to me as an attempt to fix or throw out. I replaced the Backlight LEDs and now the screen lights up, but there is no image/display. If I play with the up/down buttons I can get the display to change from black to garbled. I can't get sound from HDMI but not sure of what input is selected. I have no remote control. When I connect a laptop to the HDMI ports it recognizes a Panasonic TV for display and sound output but I can't see or hear anything through the TV. This makes me think the mainboard is OK, but not sure if mainboard can... -
Hello there,
I have a SF314-41 motherboard that i bought impulsively recently, the problem is that i only bought the motherboard only, nothing else. When i tried powering on the board with 19V (soldered on the DC IN port), and then shorting the pin 1-2 of the keyboard, the board is turning on (as indicated by the fan), however it seems like the board is displaying on the internal display as connecting to a display on the HDMI (external) does not display anything.
I tried connecting a USB keyboard, the keyboard is powered on, however pressing numlock do nothing (supposed to toggle... -
Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
Hi all,
my display shows some strange bevahior. The backlight turns on, off and then stays on but i get no display or Acers logo. After some time it goes into standby. My notebook identifys the screen when i connect it by HDMI but i don't get an image.
Voltages seem normal and the only possible problem i found is the cap on C33 on the tcom board. It shows 0 Ohm and 0V in diode testing. Any ideas for next steps or what i can check?... -
Eventually discovered a burn mark near lower corner of LCD. Here is a summary- Backlight on, no image
- Disconnect right buffer board (view from front), left side display comes on
- Masked off pin 7+8 (both ~12,5v on both left and right buffer board) from t-con to right buffer board (view from front) display works but have some lines
- Buffer board is pretty simple
07-11-2025, 04:04 PM
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