Laptop screen remains black when I turn it on (worse after a fix)

Hi and welcome to the Forum
Depending on what you were doing before this first happened it loos as if you might have a RAM problem. I would suggest running Memtest to see what that finds. Here's a link to how to use Memtest by making a bootable CD:
Memtest86 - Download now!
You need to run memtest for a long time, at least overnight! memtest will continue to run until you stop it. Run it until it finds an error. Then you need to remove one of your Memory modules so by a process of elimination you eventually find the fauty one.
If after running overnight, say up to 10 hours if Memtest has found no errors then you can assume that our RAM is OK.
After that I would run Windows Offline Defender in the same way, ie create a bootable CD from here:
Microsoft
Report back here with your findings.
When you can get into your machine it would be helpful if you fill in your System Spec details see here:
System Info - See Your System Specs

There are 2 parts to the W7 startup. The first part "Starting Windows" is in a black screen with the coalescing squares, the second part "Welcome" is in a blue screen.

In general, the Starting Windows part deals with hardware - starting the devices in the PC and initializing their drivers. The Welcome part deals with Windows OS loading and configuration settings. So it is important for us to know where in the Startup the problem occurs. (I say "in general" because there is some overlap.)

If Windows can complete it's startup in Safe Mode then this is a very good indication that the problem is with a device driver or configuration setting.
So there next question needs to be: have you made any recent changes to your system?

jay0514 said:

So previously my laptop would go black just after the Windows 7 Welcome screen, the mouse pointer turning in that wheel
(I could access the main windows background only through safe mode)
I found a popular method that seemed to have worked for a lot of people.
I removed the battery, held the power button down for 2 minutes, put the battery back in, plug in power cord) but now the screen goes black straight away, doesn't even get to the welcome screen.

Any ideas?

Hi jay0514.

Welcome to the community.

Please let us know if you are able to access BIOS on the system now? Does it goes black after the system manufacturer logo and before windows logo appear?

If you have a external monitor then kindly connect it to a external monitor to check if it is no video issue on the laptop.

Keeps us posted with your findings.

TVeblen said:

If Windows can complete it's startup in Safe Mode then this is a very good indication that the problem is with a device driver or configuration setting.

I, perhaps wrongly, assumed from the original post that the machine would show the "main Windows background" but go no further. I assumed that the OP would have made it clear if he could boot up in safe mode. But then the post is a bit sparse on detail!

Yes, it's like solving a puzzle sometimes!
It doesn't mean that testing the memory should not be done.

Hi jay0514,

Thanks for your reply. As you are not getting any video on the LCD it seems either the LDVS cable is not properly connected to LCD requires replacement.

You need to reseat the LCD cable to ensure it is properly inserted. Kindly update your system specs here by following this.

Also, regarding system is unable to boot you can follow the steps outlined in the link below:

Troubleshooting Windows 7 Failure to Boot

Keep us posted with the results so we can advise you further.