|If you DO have video while booting BEFORE the operating sytem is supposed to load, but NO video after that, that problem is easy to fix, if there's nothing wrong with the hard drive or the data on it. |
If you have no video at all from the built in display....
Since it last worked properly....
- have you dropped this laptop ?
- have you spilled liquid on it ?
Either of those is the most common reason major pieces need to be replaced because they're damaged.
- have you installed ram that was not installed in this laptop before ?
If so, installing ram that is not 100% compatible with using it in your mboard can cause the system to NOT fully boot.
If you still have the ram that was in it before, try installing only that ram.
- have you been fiddling with the ram otherwise ? A poor connection of the ram in it's slots can cause your symptoms.
If none of the above applies....
You SHOULD hear one short mboard beep while booting if the bios has completed it's POST successfully.
It takes about a second for you to say:
one thousand and one.
The beep should be finished before you have finished saying one.
If you hear NO beep, or any other beep(s), such as a long one or a pattern of beeps, tell us what you're hearing.
A weak or dead cmos battery cannot cause no video.
A defective hard drive or damaged data on it cannot cause no video BEFORE the operating system is supposed to load while booting unless it's connection is shorted, which is extremely unlikely. You could try removing the hard drive when the main battery and the AC adapter's connection have been removed but that probably will not help.
Laptop hard drives make very little noise, and may make occasional clicking sounds when they are working fine. It's only abnormal if they make clicking sounds continuously that there's probably a problem.
If you normally need to enter a system access password to use the computer at all or to access the hard drive, or if you don't have those, to Logon to Windows, the hard drive led will stop blinking shortly after the boot sequence gets to that point.
If you flashed the bios just before this first happened, using the wrong bios update or the wrong flash utility version, or something going wrong during flashing, can trash your bios, and in that case the mboard cannot work normally and you will usually have no video, from the built in display, or from an external montor.
If nothing else is wrong, it's common for you to get no video from the built in screen, especially after the comuter has been used a lot, if you have either of these problems....
Laptop no video (or video problems), and battery, AC adapter, power jack T shooting.
See response 1:
DO NOT plug in or unplug a monitor's video cable into / from a video port while the computer is running. Doing so can damage the monitor's circuits and/or the video adapter's circuits.
Some laptops will display on an external monitor without you having to do anything.
If you get no video on an external monitor, some laptops have a key combo that you must press to toggle the display to external video only / built in display video only / sometimes both - see the Owner's or User's manual for the model.
If there is nothing wrong with your AC adapter or it's connection and the jack in the laptop.......
Laptop main batteries usually work as they should for a year or so, then they begin to rapidly deteriorate. From what I've seen, by two years they cannot be charged to anywhere near their full capacity, and it gets worse after that.
They often develop internal shorts when they are older. If the battery gets HOT rather than just warm after you have attempted to charge it for at least a half hour, or after you have been using the laptop for a while with the AC adapter plugged in, it's definitely internally shorted and you must replace it. Internally shorted batteries getting too hot have been known to cause the laptop to catch on fire.
Tips about battery charging problems on Dell laptops - may apply to other makes.
See response 3 in this by iTech: