Before Opening This Laptop Up (dead Monitor?)

I get nothing on the screen, just black from power on etc. I checked drivers and Bios AND RAM, no issues. When plugging an external monitor, I can see everything.

Is there a chance it's the MoBo video port? maybe a wire jarred loose? Is it worth it on either of these?

The reason I ask is because I have replaced LCDs with no problem, usually $50-75 for new LCD and then like $50-75 to put it in. However if it is a deeper issue or the motherboard, probably not worth the $$$.

 

With the laptop booted up, shine a bright light directly at the display. Look for some faint text or graphics on the screen. If you do see something, you may have a bad inverter or backlight. Older displays use cold-cathode fluorescent lamp. The lamp is powered by an inverter board, which sometimes fail. Replacement inverter boards are relativity inexpensive and not to difficult to replace.

More recent displays use LCD backlighting, which is more reliable.

 

Yeah, you provided no information about the make and model of the notebook but I agree with PokeyBoy, this sounds like a backlighting issue and sticking your nose up close while shining a flashlight into the screen to see if you can see your Windows desktop is the best way to determine if it is a backlighting issue or not. The problem here is CCFLs and inverters have not been used in notebooks for some time now, having been replaced by LEDs. So if you do see your desktop, and this is an old notebook, finding parts may be a challenge, and the cost of those parts may not make it worthwhile to repair an old notebook.

Since an external monitor works fine, I am assuming you know how to flip the video output between internal, external and both monitors. And since you do get a display on the external monitor, it is most likely your motherboard is fine and if me (and if you see nothing with the flashlight), I would suspect the cable connection between the motherboard and internal monitor. That could be a connector problem, or a pinched or broken wire/cable.

 

You can try
Switch off
Disconnect power supply
Remove battery
Press and hold power button for 10-15 seconds
Give it a few minutes, after this, only 3 to 4 minutes
Then reconnect power supply , BUT LEAVE BATTERY OUT)
If it shows a screen image, allow it to run for a while- something like 10 to 15 minutes at least
Then shut down,and replace battery.
Restart
This often works with old laptops

 

I believe that is irrelevant with my issue with the exception of yes it is most likely it is old enough to be a backlight issue, however turning all light off or shining a flashlight onto the screen shows nothing. I found a backlight for $15 but if that isn't the issue, it's like burning a $10 and a $5. It is an HP DV7 I believe. It is old enough to have had Vista on it but new enough that I am running Windows 10 Pro now with no issues, with the exception of having to use an external monitor.

 

Well, news.....
It cut on and looked great. I installed Windows 10, downloaded some stuff, played around for a while. Cut it on the next day and2 days later, and then again, Sunday. Today? POOF!!!! Gone! nothing on screen.

 

You forgot to tell us what you tried to get it working - just in case there are other suggestions for you