Versión actual por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| Since you have replaced the LCD screen it seems that the problem is on the motherboard. | |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. | |
| === Update (09/28/2022) === | |
| Hi, | |
| I was hoping that there may have been something like Wistron??? or Compal LA- ??? printed somewhere on the board. | |
| Dell doesn't make boards. Boards are made to order for it by specialist board manufacturers. | |
| Unfortunately all the info you provided are Dell part numbers, not the board manufacturer's part numbers. | |
| You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. Select the appropriate model i.e. ''Schematic diagrams > Dell > Precision > 7740'' (I'm assuming this is an M7740) | |
| The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. Hopefully you have a DMM (digital multimeter) and can read schematics ;-) | |
| ***Note:*** To upload images/documents etc to your QUESTION in ifixit, click on ''Options > Edit'' (to the right of your question) and then place the mouse cursor where you want to enter the text etc and then click on the ''envelop icon'' in the header bar at the top of the edit and follow the prompts. | |
| === Update (09/29/2022) === | |
| Hi, | |
| Without seeing a schematic the following is only a guess as to what it might be. | |
| a). Best case it that there is an onboard smd (surface mount device)fuse in the backlight supply and that it has blown. Fuses on the board are marked with an F designation. Maybe check for any fuses in the vicinity of the video cable connector on the board.However in saying this there's always a reason why a fuse blows so if you find one that has you have two problems - i). knowing its specifications and ii). finding out why it blew in the first place. That's where the schematics come in handy as it gives the specs or model number of all the components on the board. Also the wiring diagram etc.. It may well be that there was a problem in the original LCD panel that caused it to blow. | |
| b). There is no fuse but there's an IC (usually a mosfet) that is in the supply path and it has failed, either due to component failure - rare but it does happen or again some other problem caused it to fail - LCD panel problem hopefully. | |
| Looking at images of your board online it seems to have a protective cover over most of the board so it was difficult to see the board but if you're keen you may want to remove that cover (detaches somehow?) and check for any obvious component failures e.g. burnt out IC etc - you can't see a blown fuse unless it was a spectacular failure so you'll need a DMM (digital multimeter) to test them for continuity. | |
| + | |
| + | It may be that there are reputable, professional laptop repair services in your location that can fix it. Perhaps check if there are any who state that they handle Dell products (authorized repairer?) as they usually have access to the schematics and/or experience with what may have caused this to occur. |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| Since you have replaced the LCD screen it seems that the problem is on the motherboard. | |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. | |
| === Update (09/28/2022) === | |
| Hi, | |
| I was hoping that there may have been something like Wistron??? or Compal LA- ??? printed somewhere on the board. | |
| Dell doesn't make boards. Boards are made to order for it by specialist board manufacturers. | |
| Unfortunately all the info you provided are Dell part numbers, not the board manufacturer's part numbers. | |
| You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. Select the appropriate model i.e. ''Schematic diagrams > Dell > Precision > 7740'' (I'm assuming this is an M7740) | |
| The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. Hopefully you have a DMM (digital multimeter) and can read schematics ;-) | |
| ***Note:*** To upload images/documents etc to your QUESTION in ifixit, click on ''Options > Edit'' (to the right of your question) and then place the mouse cursor where you want to enter the text etc and then click on the ''envelop icon'' in the header bar at the top of the edit and follow the prompts. | |
| + | |
| + | === Update (09/29/2022) === |
| + | Hi, |
| + | |
| + | Without seeing a schematic the following is only a guess as to what it might be. |
| + | |
| + | a). Best case it that there is an onboard smd (surface mount device)fuse in the backlight supply and that it has blown. Fuses on the board are marked with an F designation. Maybe check for any fuses in the vicinity of the video cable connector on the board.However in saying this there's always a reason why a fuse blows so if you find one that has you have two problems - i). knowing its specifications and ii). finding out why it blew in the first place. That's where the schematics come in handy as it gives the specs or model number of all the components on the board. Also the wiring diagram etc.. It may well be that there was a problem in the original LCD panel that caused it to blow. |
| + | |
| + | b). There is no fuse but there's an IC (usually a mosfet) that is in the supply path and it has failed, either due to component failure - rare but it does happen or again some other problem caused it to fail - LCD panel problem hopefully. |
| + | |
| + | Looking at images of your board online it seems to have a protective cover over most of the board so it was difficult to see the board but if you're keen you may want to remove that cover (detaches somehow?) and check for any obvious component failures e.g. burnt out IC etc - you can't see a blown fuse unless it was a spectacular failure so you'll need a DMM (digital multimeter) to test them for continuity. |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| Since you have replaced the LCD screen it seems that the problem is on the motherboard. | |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. | |
| === Update (09/28/2022) === | |
| Hi, | |
| I was hoping that there may have been something like Wistron??? or Compal LA- ??? printed somewhere on the board. | |
| Dell doesn't make boards. Boards are made to order for it by specialist board manufacturers. | |
| Unfortunately all the info you provided are Dell part numbers, not the board manufacturer's part numbers. | |
| You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. Select the appropriate model i.e. ''Schematic diagrams > Dell > Precision > 7740'' (I'm assuming this is an M7740) | |
| The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. Hopefully you have a DMM (digital multimeter) and can read schematics ;-) | |
| - | ***Note:*** To upload images/documents etc to your QUESTION in |
| + | ***Note:*** To upload images/documents etc to your QUESTION in ifixit, click on ''Options > Edit'' (to the right of your question) and then place the mouse cursor where you want to enter the text etc and then click on the ''envelop icon'' in the header bar at the top of the edit and follow the prompts. |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| Since you have replaced the LCD screen it seems that the problem is on the motherboard. | |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. | |
| === Update (09/28/2022) === | |
| Hi, | |
| I was hoping that there may have been something like Wistron??? or Compal LA- ??? printed somewhere on the board. | |
| Dell doesn't make boards. Boards are made to order for it by specialist board manufacturers. | |
| Unfortunately all the info you provided are Dell part numbers, not the board manufacturer's part numbers. | |
| You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. Select the appropriate model i.e. ''Schematic diagrams > Dell > Precision > 7740'' (I'm assuming this is an M7740) | |
| The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. Hopefully you have a DMM (digital multimeter) and can read schematics ;-) | |
| + | |
| + | ***Note:*** To upload images/documents etc to your QUESTION in ifixt, click on ''Options > Edit'' (to the right of your question) and then place the mouse cursor where you want to enter the text etc and then click on the ''envelop icon'' in the header bar at the top of the edit and follow the prompts. |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| Since you have replaced the LCD screen it seems that the problem is on the motherboard. | |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. | |
| === Update (09/28/2022) === | |
| Hi, | |
| - | I was hoping that there may have been something like Wistron??? or Compal LA ??? printed somewhere on the board. |
| + | I was hoping that there may have been something like Wistron??? or Compal LA- ??? printed somewhere on the board. |
| Dell doesn't make boards. Boards are made to order for it by specialist board manufacturers. | |
| - | Unfortunately all the info you provided are Dell part numbers, not the manufacturer's |
| + | Unfortunately all the info you provided are Dell part numbers, not the board manufacturer's part numbers. |
| - | You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. Select the appropriate model i.e. |
| + | You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. Select the appropriate model i.e. ''Schematic diagrams > Dell > Precision > 7740'' (I'm assuming this is an M7740) |
| The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. Hopefully you have a DMM (digital multimeter) and can read schematics ;-) |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| Since you have replaced the LCD screen it seems that the problem is on the motherboard. | |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. | |
| === Update (09/28/2022) === | |
| Hi, | |
| I was hoping that there may have been something like Wistron??? or Compal LA ??? printed somewhere on the board. | |
| Dell doesn't make boards. Boards are made to order for it by specialist board manufacturers. | |
| Unfortunately all the info you provided are Dell part numbers, not the manufacturer's board number | |
| You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. Select the appropriate model i.e. schematic > Dell > Precision > 7740 (I'm assuming this is an M7740) | |
| - | The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. Hopefully you can read schematics ;-) |
| + | The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. Hopefully you have a DMM (digital multimeter) and can read schematics ;-) |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| Since you have replaced the LCD screen it seems that the problem is on the motherboard. | |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. | |
| === Update (09/28/2022) === | |
| Hi, | |
| I was hoping that there may have been something like Wistron??? or Compal LA ??? printed somewhere on the board. | |
| Dell doesn't make boards. Boards are made to order for it by specialist board manufacturers. | |
| Unfortunately all the info you provided are Dell part numbers, not the manufacturer's board number | |
| - | You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. Select the appropriate model i.e. schematic > Dell > Precision > M7740 |
| + | You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. Select the appropriate model i.e. schematic > Dell > Precision > 7740 (I'm assuming this is an M7740) |
| The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. Hopefully you can read schematics ;-) |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| Since you have replaced the LCD screen it seems that the problem is on the motherboard. | |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. | |
| === Update (09/28/2022) === | |
| Hi, | |
| I was hoping that there may have been something like Wistron??? or Compal LA ??? printed somewhere on the board. | |
| Dell doesn't make boards. Boards are made to order for it by specialist board manufacturers. | |
| Unfortunately all the info you provided are Dell part numbers, not the manufacturer's board number | |
| - | You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. |
| + | You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. Select the appropriate model i.e. schematic > Dell > Precision > M7740 |
| The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. Hopefully you can read schematics ;-) |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| Since you have replaced the LCD screen it seems that the problem is on the motherboard. | |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. | |
| === Update (09/28/2022) === | |
| Hi, | |
| I was hoping that there may have been something like Wistron??? or Compal LA ??? printed somewhere on the board. | |
| Dell doesn't make boards. Boards are made to order for it by specialist board manufacturers. | |
| Unfortunately all the info you provided are Dell part numbers, not the manufacturer's board number | |
| - | You could try this [link|http://laptop-schematics.com/|schematic] and see. |
| + | You could try this [link|http://laptop-schematics.com/|schematic] and see. I couldn't find one for your exact model. |
| The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. Hopefully you can read schematics ;-) |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| Since you have replaced the LCD screen it seems that the problem is on the motherboard. | |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. | |
| === Update (09/28/2022) === | |
| Hi, | |
| I was hoping that there may have been something like Wistron??? or Compal LA ??? printed somewhere on the board. | |
| Dell doesn't make boards. Boards are made to order for it by specialist board manufacturers. | |
| Unfortunately all the info you provided are Dell part numbers, not the manufacturer's board number | |
| You could try this [link|http://laptop-schematics.com/|schematic] and see. | |
| - | The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. |
| + | The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. Hopefully you can read schematics ;-) |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| Since you have replaced the LCD screen it seems that the problem is on the motherboard. | |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. | |
| + | |
| + | === Update (09/28/2022) === |
| + | Hi, |
| + | |
| + | I was hoping that there may have been something like Wistron??? or Compal LA ??? printed somewhere on the board. |
| + | |
| + | Dell doesn't make boards. Boards are made to order for it by specialist board manufacturers. |
| + | |
| + | Unfortunately all the info you provided are Dell part numbers, not the manufacturer's board number |
| + | |
| + | You could try this [link|http://laptop-schematics.com/|schematic] and see. |
| + | |
| + | The model number is very close to yours so hopefully the only difference would be minor. Unfortunately you have to buy it. |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| They will be very faint if they are there so trying this in a darkened room may help. | |
| ''If you can detect images'' you have a LCD backlight power problem. | |
| - | Since you have replaced the LCD screen it |
| + | Since you have replaced the LCD screen it seems that the problem is on the motherboard. |
| With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. | |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. |
Estatus:
open
Editado por: jayeff
Texto:
| Hi, | |
| Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. | |
| - | If you can detect images you have a LCD backlight power problem. |
| + | They will be very faint if they are there so trying this in a darkened room may help. |
| + | |
| + | ''If you can detect images'' you have a LCD backlight power problem. |
| Since you have replaced the LCD screen it must be on the motherboard. | |
| - | With a lot of laptop's e.g. HP, Lenovo, Dell, they're designed so that there is always backlight power being supplied to the screen but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. |
| + | With a lot of laptop's e.g. HP, Lenovo, Dell etc, they're designed so that there is always backlight power being supplied to the screen from the motherboard but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. |
| What is the make and model number of the motherboard (printed on motherboard)? | |
| Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong. |
Estatus:
open
Aporte original por: jayeff
Texto:
Hi, Try shining a torch at an angle close to the laptop's screen and check if you can detect any images at all when the laptop is on and there should be a display i.e. toggle the display to be either laptop only or both external and laptop and not external only. If you can detect images you have a LCD backlight power problem. Since you have replaced the LCD screen it must be on the motherboard. With a lot of laptop's e.g. HP, Lenovo, Dell, they're designed so that there is always backlight power being supplied to the screen but it is turned on and off in the screen by a signal voltage being turned on or off on a backlight enable lead from the motherboard. What is the make and model number of the motherboard (printed on motherboard)? Knowing this will make it easier to hopefully find the schematics for the board to find out what's wrong.
Estatus:
open