Insprion 14 from the Vista era

I've had an Inspiron 14 from the Vista era in my possession for a while with a dead screen, I'm wondering if anyone knows if this is a known thing from that computer's era and what the most likely culprit is if an external monitor works. My guess was the cable since it was the prior owners only computer and was opened and closed frequently.

 

Is it a 1420? If it works on an external display chances are it's a bad LCD or inverter. Unless, of course, it has Nvidia graphics...

 

If an external monitor works then there isn't a problem with the graphics chip. If there's an image on the screen but its dark, it could be a bad inverter or dead backlight. These parts should not be expensive and the inverter is fairly easy to replace if you've opened up laptops before, but the backlight is more complicated as you'll have to do some soldering and be careful with the fragile light tube. If there's no image on the screen at all, check that the cable is properly connected at both ends. If you can find a replacement cable cheap, you could try that as well because sometimes the conductors within the cable break. If none of these works then probably the lcd is bad as Commander Wolf mentions and I would suggest just using it with the external monitor because a replacement won't be cost effective on such an old machine.

 

Usually true, but not necessarily 100% of the time. The external display test will never generate false negatives (it'll never fail to verify that you do have a bad GPU), but it may generate false positives... I have definitely seen one or two cases (out of tens) of bad Nvidia GPUs where it still works fine on an external display and not the internal one.

 

It's not an nvidia GPU, I'm going to add insult to injury and mention I not longer have the brick and me already yanked the machine apart. From what I can remember however the screen was non-func not just dark. I'm pretty sure either myself or my ex-wife did the flashlight thing to the computer before replacing it.