Previously Working Computer Monitor Says Invalid Format

[Gerdr]

I was browsing the internet and all of a sudden, screen goes to thin green and some other color (I think it was purple) vertical lines, and is unresponsive. Power button doesn't work, so had to unplug computer. When restarting, it shows the windows things coming together, then gives the screen that allows you to choose safe mode, safe mode with networking, safemode with command prompt, and run normally. I've tried every option, but no matter what once I choose it goes to black screen. If I choose safe mode, it does the list of loading things and then when it reaches amd driver, it turns to black screen.

I'm using an AMD 7870 on Windows 7 something. I plugged in my old computer to see if it is the monitor, but the other computer does work.

Also, when the screen goes to black after starting my tv monitor says "invalid format". I don't know how to fix this, since I can't do any options since once I start it it goes black!

I've never had to deal with anything in that black and grey realm of safe booting and bios and whatnot, how the hell do I fix this?

Update: After a while I restarted it and got the windows sound to play, but the login screen was horribly corrupted. I was able to type in my password and login, after which the screen turned to thin vertical lines of dark and light blue and was thereafter unresponsive. I just restarted again, did everything the same, and now it is back to black screen and no windows sound playing.

Also, I have no other monitor available.

 

[Gerdr]

Update: Update: After a while I restarted it and got the windows sound to play, but the login screen was horribly corrupted. I was able to type in my password and login, after which the screen turned to thin vertical lines of dark and light blue and was thereafter unresponsive. I just restarted again, did everything the same, and now it is back to black screen and no windows sound playing.

 

[Ralston18]

Gerdr,

First download and install the newest driver for the card if at all possible.

If not then here are some things to try from easiest to hardest:

Are you using the HDMI or DVI connector on the 7870 card?

Try another cable as appropriate for the connector you are using: i.e., HDMI or DVI.

If that does not work try the other connector: i.e., if using HDMI then disconnect and try DVI. Or vice versa.

Failing all that open the case and make sure the AMD 7870 is securely seated and that the fans are all running (no overheating).

Last of all. Remove the AMD card and see if you can restore functionality via the built in motherboard graphics card.

If you can get anything to work then try to download the newest driver. Reinstall the AMD 7870 and go from there.

Perhaps a bit tedious but necessary to narrow down the problem and work towards a solution.