Laptop screen blank (screen black), but machine works and works with external monitors

[redstreit]

My laptop is Toshiba Satelite c640 AMD E-450 APU 1.65 GHz , OS Windows 7 64bt, 2 Gb RAM, and AMD Radeon HD 6320 Graphics.

Last night my laptop works normally, but after I tried to turned it on few hours ago and only show black screen although the machine, fan and indicator lamps work fine.

It happens frequently before and before I only needed to turned it off and unplug charger (the battery is broken so I only use the charger), wait for 5-10 minutes and plug the charger and it will turn on normally. Also, it previously can't restart, and I have to use that method but only for a minute to make it work again. However, the method not working now, the screen stay blank.

I try to plug it to external monitor and it works fine, And with external monitor I can restart normally. I can access desktop, but the laptop screen still blank. I tried use fn+f5 and windows+p to change display nothing happen. When I see in display setting it only show one 1 display which is the external monitor, as if it doesn't recognizes the lcd laptop itself. I've also tried hard reset and it still doesn't work.

 

[Saga Lout]

Does it shows as having a problem in the list in Control Panel>Device Manager>Monitors? You may need to open up the case to check the very delicate ribbon cable connection to the screen is in place, firmly clipped down and perfectly straight.

Before trying that, search for and download the service manual for that model. Then you will need a needle, a 2.5 Phllips screwdriver and an old bank or credit card. Post back for more details if it gets that bad.

 

[redstreit]

I tried connect it to 2 different external monitors with VGA cable, in device managers> monitors only show generic non PNP monitor for both of them which I assume it's the external monitor. Can it be driver problem?

 

[Saga Lout]

No, the standard driver is a generic file named monitor.sys.

It might be worth uninstalling the device and turning off the machine. Unplug the external at that stage and restart. It will reinstall and might just come back in a better frame of mind.

 

[redstreit]

tried uninstall it but when I turn back the laptop on, it still have black screen. I try to connect it to external monitor again in the Device Manager still shows Generic PNP monitor, however in screen resolution before I uninstalled it, in the display column it said Unknown Display Device, now it says Display Device on VGA. And there is only one display, so I think it still don't recognize my laptop LCD screen.

 

[Saga Lout]

Time to get the tools out by the sound of it. If you don't feel like doing it yourself, take it to a professional PC Fixer. It's way under an hour's work and shouldn't cost a lot.

If you don't use the laptop as a mobile device, adjust the power options as to what happens when the lid is closed, shut the lid and use a USB or Bluetooth keyboard and mouse and only open it to switch the machine on.