Computer has a black screen and will not boot or start up
May 26th, 2010 | Author: Mitz
Free Computer Help By Mitz
Rarely do I come across a problem with a computer that I cannot diagnose, however getting a black screen on boot can stump me sometimes. I always try to trouble shoot the problem manually, without using those fancy programs, because I believe it is the only way to learn.
There are two types of black screens that can appear. One that will have a beep sequence sounding to let you know what the problem could be, and the other has nothing at all. No beeps, no cursor, no logo screen, and no choice to boot to safe mode or access the bios.
If you get a beep sequence, I am not saying it is good news, however it is a step in the right direction towards solving this problem. This is a message from your computer that can be understood by looking up your bios (the brand) beep code. For example you may have an Award Bios, Ami Bios, Phoenix BIOS, compaq, Dell, or Acer Bios. This list goes on and on. You can search for Bios beep codes in google. Here is an example of results in google search Search results for “bios beep codes”
If you heard a single beep, then the computer posted, and the CPU is ok. POST= Power On Self Test A procedure the computer goes through on starting to ensure all is well.
When you get the black screen, and absolutely nothing else, this is where the challenge begins. Sometimes the fans and the cpu seems to be running.
When this happens to me, I have an instant advantage as I have a replacement part for basically any computer component at my fingertips.
Common things that can happen when your computer has a black screen:
- At boot up, it sound like it is booting as the cpu fan is running and the lights are on. It also finds the cd rom but it won’t boot from a cd either.
- Sometimes it will boot to a black screen and the power switch light will be green and then turns to orange or amber. Everything is running.
- Everything seems to be running but you can’t see anything on the screen, not even a flashing cursor.
Some common causes for a computer to have a black screen at bootup:
Where is your Monitor plugged in?
The first and most obvious reason for a computer appearing to run but you cannot see the video is the monitor. A common mistake is to plug the monitor into the onboard video plug when you actually have a PCI or AGP video card installed. Trust me I have done this myself. Simply move the plug to the correct position.
Failing Display adapter or video card can cause a black screen:
Most of the time you can tell if your computer video card is deteriorating by seeing little tell tale signs. Lines appearing or flashing can sometimes occur, however sometimes nothing happens at all. You might turn your computer on and have the dreaded black screen. You can try removing your video card and using onboard video, or replacing the video card to see if that is the problem.
The next reason is RAM…or memory: This can cause a black screen on your computer.
If your memory is not seated properly (not in), is damaged, or even absent altogether, this can cause major problems.
- If you have no memory installed at all, some computers make no sounds and just show a black screen. Other computers go crazy and beep their head off. I am an expert at this one, as I build so my computers.
- When your computer gets a black screen only sometimes, it usually means your ram is on the way out..For example if you boot your computer and it doesn’t work, then go back an hour later, and it does work, your memory is playing up. You can try taking the ram out, gently cleaning it with an antistatic cloth, and replacing it. This may solve your problem. If it does not, then you should try running your computer with another compatible stick of ram installed.
If you plan to open your computer case and remove the ram please read these articles How to open a computer case safely and Upgrade Memory
Installing new hardware
Often when computer users install hardware in order to upgrade their own computers they run into problems. If you have just performed an upgrade and then get a black screen, the answer is obvious. Some hardware components may not be compatible with the others in your system. And of course there is always the risk of static electricity damaging your components when you are not an experienced computer repair person.
Leaving a bootable usb flash drive connected to your computer.
Yes this can confuse your computer and it won’t know where to boot up. I have had a black screen from doing this and have realised and removed the usb and the computer just continues to boot normally..
Corrupting the Boot Sector.
I have learnt this lesson the hard way. Never turn off the computer when it is half way through the boot procedure. Even when it is taking forever, or having a major problem you must let it run through if possible. Interrupting it once may be ok, but twice or three times is a no no. After you have carelessly restarted and shutdown a few times the black screen may appear. But this time it may be beyond repair for the average computer user. How to repair a damaged boot sector by replacing the master boot record (MBR) in Windows XP
Your CPU is not correctly seated.
After transporting a computer from one house to another, this is the first place I look. Transporting a working computer, and then not working with a black screen = dislodging the CPU. You can fix this easily by removing the CPU fan and carefully replacing it back in its spot. You may also have to replace some thermal paste between the cpu and heat sink as it stops the cpu from overheating.
Keyboard Faulty
This one surprised me because when there is a problem with the keyboard the computer still boots and says that there is no keyboard detected on the screen. Well this didn’t happen for me. I had a keyboard with a bent pin on the cable, so when it was plugged into the computer, it just plugged in normally. Then the computer had a black screen, you could here it starting up but no posting beeps, no display, nothing. I even swapped monitors around until finally I tested the keyboard and found the bent pin. I never thought to look there because of the usual default message that appears on the screen when there is something wrong with your keyboard.
Notes relating to your computer having a black screen:
- If your computer has black screen but you can see one small flashing cursor, I see this as a good sign! It usually means your computer is ok to be formatted. It can also mean that you should try to repair the boot sector first. How to repair a damaged boot sector by replacing the master boot record (MBR) in Windows XP
- Lets face it.. Having a black screen is a common symptom for so many problems.
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25 Responses to “Computer has a black screen and will not boot or start up”
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Hi, thanks for your advice. My Problem: Twice in two days my PC (Windows XP)displayed a black screen. Nothing else. Onstart there was one beep. The reset button did not restart my PC, the shut down button did not shut down PC. I had to turn off the power, wait some seconds there turn power back on. This time when I turned on my PC it booted up just fine.
Thanks.
Elef
I just had this issue and the problem, I believe, was related to an expired McAfee. I had tried restoring from a previous good boot but it didn’t work. After hours of restarting the computer and trying various tricks, I finally shut the computer off as it was loading drivers. The next time I started the computer it realized something was wrong and tried to recover. I was able to get to a command prompt and execute explorer.exe. When the computer restarted I was able to get to windows. At that time I noticed that my free McAfee from Comcast had expired (because Comcast went to Norton). I downloaded the free Norton, which uninstalled McAfee, restarted the computer and everything has been fine.
This got my “major” failure fixed as soon as I read about the RAM. I had already tried booting from disks and trying to get in through DOS and keyboard button combos and nothing would solve it.
-Then I was reminded of my recent RAM install that worked well for months may possibly have an issue, and Bada-bing! solved. Thanks!
Its great that we can sometimes fix the problem when your computer has a black screen.. Some people are lucky as the black screen problem appears to magically go away and stay way…Other times the black screen is just a warning that something is starting to go wrong and packup. Hope this post can help. I have added to this article as the problems cropped up… It amazes me how many solutions and causes there are for the one symptom.
The most comprehensive and very well thought out information I have found on this subject on the net. Keep on writing, I will keep on stopping over to read your new content. This is my fourth time coming by your website
Have the same problem with my computer. one pc when i turn it on it just displayed no signal cable connected. no post message, no bios. swap the psu and ram to other computers, still the same problem. i even try my old video card, still no response.. i try clearing the cmos battery based on what i read in other post. now it has a black screen only( my fault). is my mother board defective??
jessa, what video chipset does your computer have? My computer had the nVidia chipset, which was defective. (You can google “Nvidia defect” and find tons of information surrounding the defect, the companys that were affected, ie, Dell, HP, Toshiba, etc., class action suits, the settlements, and various other information). I had numerous symptoms including, black screen, blue screen with lines, not waking from sleep mode, etc. My computer was purchased in May 2007, but I was able to file a small claim in my city just last month (June 2010) and received a settlement from HP. You’re welcome to email me if you have further questions. Actually, anyone reading this who wants more info is also welcome to email me at zeebiz@verizon.net. I don’t want to bad-mouth any product or company, but I’m for the little guy! We spend money and expect good quality products, but when those products fail and the company(ies) responsible try to downplay it or sweep it under the rug, I want fair justice.
Jessa, I have the same issue, I replaced my motherboard with no success. I also tried my cpu in a different computer and it worked. Im kind of SOL right now.
At this point I would start with the mother board and the cpu if they work together and then keep replacing parts until it doesn’t work……to find the problem. You are lucky you can try another motherboard, most people are left at that dead end because they do not have anything to replace it with.
This reminds of the good old days, repairing computers but the only difference is that I had a pile of 20 in front of me. I always used to put the black screen jobs until the end as they always took the longest… The funny thing is I never did it the easy way because I wanted to know every problem and every solution. I still don’t know all the answers to this “black screen” thing.
The other day I had two black screens on my computer…the one I use…one was my nvidia driver getting updated through Windows updates and the other was a virus program, security issue. I think it is haunting me….Of course these black screens are easy to deal with because I had an error message telling me what it was….Why can’t a computer tell you that the “hard drive is defective” or that the “video card has died”???? without having to add a computer diagnostic device.
I have the following problem.
My computer has Windows Vista Ultimate on it and yesterday I attempted to reinstall Vista Ultimate from the Original disc that I have.
The install sequence started ok and I entered the product key and the install started, the computer rebooted itself as it does periodically during the install, then all I had for the following 6 hours was a black screen with no indication as to what was happening. Then to add to my problems we had a power cut. Even though I have a battery backup that safely shuts down the computer it just ran flat with no indication of the computer being closed down.
Now, At boot up, it sound like it is booting as the cpu fan is running and the lights are on. It also finds the cd rom but it won’t boot from the Windows Vista Ultimate cd either.
It will only boot to a black screen and the power switch light will be on. Everything appears to be running but I can’t see anything on the screen, not even a flashing cursor.
I am also unable to get into the BIOS. I have no idea what is the problem here. The computer worked normally before the reinstall commenced.
It sounds like something has happened when it was interrupted. It is very hard to play around with a laptop..not as easy to remove parts or fix them. What about plugging a monitor into the spare monitor port on the back…That will check the display….Then make a copy of your cd or dvd and try using the copy to see if it will boot from there…. does it come up with “press any key to boot from cd”?
i have an onboard video ATI Radeon X1200 series. already try another monitor but still the same problem. it doesnt detect the keyboard and the mouse.all it displaying is the signal cable disconnect. will try to connect my spare dvd rom to see if it will boot. will inform you
Help! I have a Dell laptop, 18months old, Vista.
I have been editing photos with adobe lightroom for the last week or so, and I have ALL of my babies pictures as well as customers that I take pictures for on my editing software on this laptop….recently installed the lightroom program, that’s all I’ve done different, other than having alot of pictures on the memory. Booted it up this morning and it almost immediately went black, a few times it would try and boot up for a second or two and I’d see the Dell symbol, and then black again. Can hear fan for a minute like it trying to work, but that’s it. No beeping, and no other symptoms that I can remember. Can anyone offer advice as to my next course of action? I’m not at all savy in computer hardware or repair, so I don’t have any clue…please help!
Have you tried booting into safe mode?
hello mitz,
my computer has no post message, no bios, even the keyboard and the mouse has no power.. i tried connecting my dvd rom to reformat it but still it cannot detect any accessories. all it displaying is signal cable disconnected.
I have a Dell desktop computer & It is about 3 or 4 years old. I’m using Windows XP. Just earlier today, I was doing what I usually did & that was just surfing around on the internet..a blue screen popped up out of no where & it mentioned not having a software or hardware fully installed. It has popped up with the same error about 3 times but everytime I shut down the pc & start it back up, It works fine. This time I tried to do the same thing & the dell thing loaded up but after that..the screen went black. I tried starting it up another 3 times because I was confused & kept getting the black screen.
I must add that there was no sounds. I am not good at repairing computer’s so could someone please help me out?
Hi Candice…
Ouch…A Blue screen of death (BSOD) is a warning that something is failing and it will usually tells you what is wrong by providing a stop code and error name in capital letters. Did you write anything down when you saw the blue screen, because now you have a black screen and the computer is not going to tell you anything now…
This is where the above article comes in…when you have a black screen and no idea what is wrong.
I have a black screen and it says it cannot find a signal coming from my computer. This happened immidietly after installing new drivers for my computer, which I may have installed wrong. What should I do?
If you can start in safe mode or even get into your computer I would do a system restore or remove what you installed. If it is a device driver go to the control panel>system icon>go to device manager or something that says devices…not sure what version you have….maybe if you have xp there is a hardware tab.
Remove what you installed if you can…
I have absolutelyno access to my computer at all. I turn it on and my computer screen does not react to it at all. Man this sucks
Hi Mitz! A most excellent and needed article, has already helped out a great deal.
But my pc’s currently suffering from black screen syndrome – newly put together with an asus p6t se motherboard – ati hd5750 – i7-930 – Giel 2gig RAM x2 – and a corsair fan/power supply set. all brand new, all not damaged and i can’t get it to boot! i feel like i’m missing a ridiculously obvious check so some more help would be very much appreciated
Don’t worry it has happened to us all…What is the computer doing? When you press the power on button, what happens? Is the screen completely black or does it have a cursor? Give me more info…the more info the better…
My daughters computer has just black screened. It is an AsRock MB, Amibios on XP. When I power up the fans start, the cd and floppy flash, the HD whirrs but there is no beep, no curser, nothing. The CPU fan starts and all these continue to run. There is a click and faint noises from the HD as if it is trying to work. I have had video cards fail before but they started to fail by collapsing mid session and them going black. Any sugestions?
IF it sounds like everything is going…like enough power going through, then I would start with the simple checks…Removing or unplugging and extras is a good start…Then I would check the ram next as it is the most common cause…Just remember that if you just open a computer and touch stuff you transfer static electricity to the components and kill them… If you do not have an antistatic strap, make sure you take other precautions when opening the computer…
Backyard techie rules
Make sure all power cords are disconnected from the computer.
Where bare feet. I know that sounds funny….
Stand on a lino or tile floor..not carpet..
Have dry clean hands..
Touch the metal casing inside the computer to release static electricity.
Now carefully touch the parts.
Please note: It is still a risk to do any electrical work yourself so proceed at your own risk. If your computer is insured then do not open it yourself as it will void your policy.
Ok,
When i connect socket to power supply, the power-on switch on the motherboard turns on indicating sleep-mode(steady red glow)
After which I turn my screen on, then main power on –
all fans rev up, including the graphics cards, and i can hear the HDD and CD drive rev up too.
Meanwhile nothings happened on screen, doesnt react to the pc turning on, just powerless black screen. ‘no signal detected’.
I’m sure my graphics card, cpu n motherboard are fine because their fans/lights are active, but I cant tell for sure about the RAM. I think theyre fine because when i remove them before start up its the same reaction.
i have a feeling its either the graphics card (since its a video response issue) or maybe keyboard?
thanks in advanced mitz – appreciating all the help!