Laptop screen doesn't always turn on (HP dv7)

[dragonflyspit]

The problem is inconsistent, but it happens more often than not. Everything powers up as normal, but the screen doesn't come on. An external monitor works fine with it.

The only time it does this is booting up. I can open and close the lid, shake it, or do anything else and I cannot make the screen turn off or on while the pc is running. It only fails to come on when it's booting up, which includes rebooting. Sometimes it will turn on 10 times in a row, and sometimes it'll only turn on only one out of ten boots, but it's inconsistent and absolutely unpredictable.

Any idea what's wrong and what I'll need to do to fix it? It won't be the first time I've had this thing apart. It has not been a reliable machine.

Thanks in advance,

K

 

[carnageX]

Does it display the BIOS splash consistently? Or does it not display anything at all?

It's possible the inverter is going out if it's not displaying anything at all, even before Windows starts booting.

You could try updating your video drivers in the mean time.

 

[dragonflyspit]

There is absolutely nothing on the screen at all. The screen remains completely black, just as though the laptop is turned off. The problem is there from the moment I press the power button, not just when Windows starts. I'm sure it has to be hardware.

What is the inverter, and how do I replace it?

 

[dragonflyspit]

Okay, so I did my research and now I know what an inverter is and how to replace it. From what I read, that seems more likely than a bad screen. It appears to be an easy and cheap fix.

Thanks for your help.

 

[Alexffiala]

Okay, so I did my research and now I know what an inverter is and how to replace it. From what I read, that seems more likely than a bad screen. It appears to be an easy and cheap fix.

Thanks for your help.

If you have a spare monitor, you can also check to see if your on-board graphics are working. Hook another monitor up and see if your screen appears there. If not, it's probably an on-board graphics problem.

 

[carnageX]

Okay, so I did my research and now I know what an inverter is and how to replace it. From what I read, that seems more likely than a bad screen. It appears to be an easy and cheap fix.

Thanks for your help.

One thing to look at first, is possibly a backlight issue as well. WHen the screen goes black like this, take a flashlight and shine it at about a 45* angle. If you can see the screen, then it would be a backlight issue.

If you have a spare monitor, you can also check to see if your on-board graphics are working. Hook another monitor up and see if your screen appears there. If not, it's probably an on-board graphics problem.

OP already said that an external monitor works fine.

 

[dragonflyspit]

I could swear I responded to this. Sorry.

I tried the flashlight with power on and off to compare them, and they are the same. All I see is a dark, seaweed green reflection from the screen.

I ordered a cheap inverter on Amazon. I feel sure you're right about this being a bad inverter, and it was little enough money to be worth the risk (under $20 with shipping).

Could my RV power source have caused this? I often run the RV off a small, 800 watt generator. It seems suspect because the shop turned the laptop on and off 10 times and it worked fine. It never works that consistently at "home." Back at the RV, it wouldn't come on again for me, and has only come on once since then. However, the screen doesn't work when running on the battery either. At the shop, it didn't have a battery in it because that also suddenly failed (at the same time as the screen and Photo Gallery thumbnail issue). I don't know whether it's normal for a battery to fail suddenly. I never had to replace one before.

 

[dragonflyspit]

I don't know whether you're still following this thread.

I got the new inverter today. It didn't fix the problem. I don't know what to think. Could a new inverter be bad right from the start? Everything I read supported the inverter being the issue rather than the screen. I sure don't want to buy a screen only to find that it's not the problem either.

Your input would be appreciated.

 

[Joe C]

9 out of 10 times, the back light fails more often

 

[dragonflyspit]

Are those the only two possibilities? Everything I read seemed to indicate the inverter. Before I spend $100 or more, is there some way to know sure what the problem is?

What goes out on the backlight? Is the part itself repairable, like re-soldering something?