To make it easier to do, if there's a display shown on an external monitor (TV?) connected to the laptop's HDMI port (press Fn + F8 both together to switch display output from laptop to external) then if you have Windows installed in the laptop go to the Power options and change the Lid switch setting to [link|https://www.tenforums.com/tutorials/107865-add-remove-lid-close-action-power-options-windows.html|do nothing] then select ''Apply''.
Restart the laptop in the normal manner and check if the laptop screen turns on.
If it does there may be a problem with the lid switch in the laptop. The switch sends a signal to the I/O chip showing whether the lid is open or closed. When it is closed the I/O chip either applies or removes (not sure which) a voltage signal on the backlight enable (BL_EN) lead to the display.
There's always power being supplied to the LCD panel backlights circuit from the motherboard (in your case you have proven this) but it is the voltage signal status on the BL_EN lead that tells the LCD panel whether to turn the backlights on or off.
-
The backlight power on the motherboard is not turned off when the screen goes dark. They're turned off in the LCD panel
+
The backlight power on the motherboard is not turned off when the screen goes dark. It's turned off in the LCD panel
Here's an image from the service manual showing in block form the power supplies to the screen.
Unfortunately without knowing the make and model number of the LCD panel so that its datasheet can be found (I can't find it anyway) I don't know which pin on the LVDS connector on the motherboard the BL_EN lead is, so that you can check.
If changing the Lid switch power setting makes no difference it still could be that there's a problem on the BL_EN lead or it is in the display panel.
To make it easier to do, if there's a display shown on an external monitor (TV?) connected to the laptop's HDMI port (press Fn + F8 both together to switch display output from laptop to external) then if you have Windows installed in the laptop go to the Power options and change the Lid switch setting to [link|https://www.tenforums.com/tutorials/107865-add-remove-lid-close-action-power-options-windows.html|do nothing] then select ''Apply''.
Restart the laptop in the normal manner and check if the laptop screen turns on.
If it does there may be a problem with the lid switch in the laptop. The switch sends a signal to the I/O chip showing whether the lid is open or closed. When it is closed the I/O chip either applies or removes (not sure which) a voltage signal on the backlight enable (BL_EN) lead to the display.
-
There's always power being supplied to the LCD panel backlights circuit from the motherboard (in your case you have proven this) but it is the voltage signal status on the BL_EN lead that tells the LCD panel whether to turn the backlights on or off. The backlight power from the motherboard is not turned off when the screen goes dark e.g. when lid is closed.
+
There's always power being supplied to the LCD panel backlights circuit from the motherboard (in your case you have proven this) but it is the voltage signal status on the BL_EN lead that tells the LCD panel whether to turn the backlights on or off.
+
+
The backlight power on the motherboard is not turned off when the screen goes dark. They're turned off in the LCD panel
Here's an image from the service manual showing in block form the power supplies to the screen.
-
Unfortunately without knowing the make and model number of the LCD panel so that its datasheet can be found (I can't find it) I don't know which pin on the LVDS connector on the motherboard the BL_EN lead is, so that you can check.
+
Unfortunately without knowing the make and model number of the LCD panel so that its datasheet can be found (I can't find it anyway) I don't know which pin on the LVDS connector on the motherboard the BL_EN lead is, so that you can check.
If changing the Lid switch power setting makes no difference it still could be that there's a problem on the BL_EN lead or it is in the display panel.
To make it easier to do, if there's a display shown on an external monitor (TV?) connected to the laptop's HDMI port (press Fn + F8 both together to switch display output from laptop to external) then if you have Windows installed in the laptop go to the Power options and change the [link|https://www.tenforums.com/tutorials/107865-add-remove-lid-close-action-power-options-windows.html|Lid switch setting to do nothing] then select ''Apply''.
+
To make it easier to do, if there's a display shown on an external monitor (TV?) connected to the laptop's HDMI port (press Fn + F8 both together to switch display output from laptop to external) then if you have Windows installed in the laptop go to the Power options and change the Lid switch setting to [link|https://www.tenforums.com/tutorials/107865-add-remove-lid-close-action-power-options-windows.html|do nothing] then select ''Apply''.
Restart the laptop in the normal manner and check if the laptop screen turns on.
If it does there may be a problem with the lid switch in the laptop. The switch sends a signal to the I/O chip showing whether the lid is open or closed. When it is closed the I/O chip either applies or removes (not sure which) a voltage signal on the backlight enable (BL_EN) lead to the display.
There's always power being supplied to the LCD panel backlights circuit from the motherboard (in your case you have proven this) but it is the voltage signal status on the BL_EN lead that tells the LCD panel whether to turn the backlights on or off. The backlight power from the motherboard is not turned off when the screen goes dark e.g. when lid is closed.
Here's an image from the service manual showing in block form the power supplies to the screen.
Unfortunately without knowing the make and model number of the LCD panel so that its datasheet can be found (I can't find it) I don't know which pin on the LVDS connector on the motherboard the BL_EN lead is, so that you can check.
If changing the Lid switch power setting makes no difference it still could be that there's a problem on the BL_EN lead or it is in the display panel.
If there's a display shown on an external monitor (TV?) connected to the laptop's HDMI port (press Fn + F8 both together to switch display output from laptop to external) then if you have Windows installed in the laptop go to the Power options and change the [link|https://www.tenforums.com/tutorials/107865-add-remove-lid-close-action-power-options-windows.html|Lid switch setting to do nothing] then select ''Apply''.
+
To make it easier to do, if there's a display shown on an external monitor (TV?) connected to the laptop's HDMI port (press Fn + F8 both together to switch display output from laptop to external) then if you have Windows installed in the laptop go to the Power options and change the [link|https://www.tenforums.com/tutorials/107865-add-remove-lid-close-action-power-options-windows.html|Lid switch setting to do nothing] then select ''Apply''.
Restart the laptop in the normal manner and check if the laptop screen turns on.
If it does there may be a problem with the lid switch in the laptop. The switch sends a signal to the I/O chip showing whether the lid is open or closed. When it is closed the I/O chip either applies or removes (not sure which) a voltage signal on the backlight enable (BL_EN) lead to the display.
There's always power being supplied to the LCD panel backlights circuit from the motherboard (in your case you have proven this) but it is the voltage signal status on the BL_EN lead that tells the LCD panel whether to turn the backlights on or off. The backlight power from the motherboard is not turned off when the screen goes dark e.g. when lid is closed.
Here's an image from the service manual showing in block form the power supplies to the screen.
Unfortunately without knowing the make and model number of the LCD panel so that its datasheet can be found (I can't find it) I don't know which pin on the LVDS connector on the motherboard the BL_EN lead is, so that you can check.
If changing the Lid switch power setting makes no difference it still could be that there's a problem on the BL_EN lead or it is in the display panel.
If there's a display shown on an external monitor (TV?) connected to the laptop's HDMI port (press Fn + F8 both together to switch display output from laptop to external) then if you have Windows installed in the laptop go to the Power options and change the [https://www.tenforums.com/tutorials/107865-add-remove-lid-close-action-power-options-windows.html|Lid switch setting to do nothing] then select ''Apply''.
+
If there's a display shown on an external monitor (TV?) connected to the laptop's HDMI port (press Fn + F8 both together to switch display output from laptop to external) then if you have Windows installed in the laptop go to the Power options and change the [link|https://www.tenforums.com/tutorials/107865-add-remove-lid-close-action-power-options-windows.html|Lid switch setting to do nothing] then select ''Apply''.
Restart the laptop in the normal manner and check if the laptop screen turns on.
If it does there may be a problem with the lid switch in the laptop. The switch sends a signal to the I/O chip showing whether the lid is open or closed. When it is closed the I/O chip either applies or removes (not sure which) a voltage signal on the backlight enable (BL_EN) lead to the display.
There's always power being supplied to the LCD panel backlights circuit from the motherboard (in your case you have proven this) but it is the voltage signal status on the BL_EN lead that tells the LCD panel whether to turn the backlights on or off. The backlight power from the motherboard is not turned off when the screen goes dark e.g. when lid is closed.
Here's an image from the service manual showing in block form the power supplies to the screen.
Unfortunately without knowing the make and model number of the LCD panel so that its datasheet can be found (I can't find it) I don't know which pin on the LVDS connector on the motherboard the BL_EN lead is, so that you can check.
-
If changing the Lid switch power setting makes no difference it still could be that there's a problem on the BL-EN lead or it is in the display panel.
+
If changing the Lid switch power setting makes no difference it still could be that there's a problem on the BL_EN lead or it is in the display panel.
Hi @lloydkwakye
If there's a display shown on an external monitor (TV?) connected to the laptop's HDMI port (press Fn + F8 both together to switch display output from laptop to external) then if you have Windows installed in the laptop go to the Power options and change the [https://www.tenforums.com/tutorials/107865-add-remove-lid-close-action-power-options-windows.html|Lid switch setting to do nothing] then select ''Apply''.
Restart the laptop in the normal manner and check if the laptop screen turns on.
If it does there may be a problem with the lid switch in the laptop. The switch sends a signal to the I/O chip showing whether the lid is open or closed. When it is closed the I/O chip either applies or removes (not sure which) a voltage signal on the backlight enable (BL_EN) lead to the display.
There's always power being supplied to the LCD panel backlights circuit from the motherboard (in your case you have proven this) but it is the voltage signal status on the BL_EN lead that tells the LCD panel whether to turn the backlights on or off. The backlight power from the motherboard is not turned off when the screen goes dark e.g. when lid is closed.
Here's an image from the service manual showing in block form the power supplies to the screen.
Unfortunately without knowing the make and model number of the LCD panel so that its datasheet can be found (I can't find it) I don't know which pin on the LVDS connector on the motherboard the BL_EN lead is, so that you can check.
If changing the Lid switch power setting makes no difference it still could be that there's a problem on the BL-EN lead or it is in the display panel.
[image|3530530]
(click on image)