Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have HP Pavilion DV4T-2100 model running windows 7. Today when I turn it on I got black screen and it is not showing anything at all. Everything else is working. I can hear fan noise, LEDs lights are blinking and even I can hear window welcome tone when window starts and also as I know my first screen is password screen when that tone is played I type password and press enter and I can hear sound that is played when user login inside system. Only thing that is missing is display as screen is completely black all time. I have done removing battery and pressing power button for 30-60 seconds many times but no success. The screen is remain black all time. Please tell me what is the problem. Is there any defect with hardware or I have to replace anything.

Edit: When connected to external monitor display is showing up but when display is switched to laptop it does not shows up anything it remains black(not completely black but bright black screen). Is there a fault with laptop screen or wire that connects with screen to other part. What is possible fault if it is working with external monitor.

Edit no. 2: Got it checked from a technician and he told me that it is motherboard fault and it needs to be replaced. Is he right about it? Please share your experience if you have replaced same problem.

Thanks in advance.

Regards, Anuj

share|improve this question

I had this same issue when I was working with a client's laptop about a week ago. The problem was that one of the wires behind the screen was being pinched, hence cutting off the signal. Worst case scenario, you may have to replace your screen.

share|improve this answer
Thanks for reply. Screen is black but its brightness is varying when windows boot up. It is not as black as its look when laptop is off. IS there any problem with graphic card or motherboard. – anujprashar Dec 31 '11 at 14:57
@anujprashar Okay, it sounded like the screen was completely black all the time. In that case, I'm not too sure. I was just excited to see your question because I would be able to offer a solution. I hope I was at least somewhat helpful. Good luck! – Rob Dec 31 '11 at 15:03
@anujprashar if you can see glints of information, then it could be a backlight being off or failed. Do the Flashlight trick, or shine some light in there, and see if the LCD pannels are still making a picture, just no backlight. – Psycogeek Dec 31 '11 at 15:10
I talked with someone who has same problem and he told me that there was problem with some display ic chip in laptop and he got it replaced and also fan of laptop replaced to get that black screen fault corrected. – anujprashar Dec 31 '11 at 16:00
OK got it checked from a technician and he told me that it is motherboard fault and it needs to be replaced. – anujprashar Jan 3 '12 at 14:28

There is an IC for display also called "display chip" which gets exhausted.

There are 2 solutions:

  1. There is a technique called "reballing" which needs to be done on that chip, basically it's a kind of soldering of the chip.
  2. You can change the chip.
share|improve this answer

First thing, try to replace the inverter. If nothing works after that, then change the cable that connects the motherboad and the display. As a last resort, if nothing else works, change the entire display.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .