I have an HP envy m6 laptop and recently i've noticed that the display with go black and show a bunch of flashing vertical lines. I replaced the cable maybe six months ago, so I checked that first and it seems ok, although I don't have another one to swap out to see for sure. I made sure all the drivers were updated. The strange thing is, when I plugged it into an external monitor to check if it's the GPU, it showed up fine on the external monitor and the display came back normally on the laptop. Also when I put the laptop to sleep and wake it up, the display comes back normally. I'm at a loss here. Any help would be appreciated.
Could be the LCD cable or invertor. If you have a external monitor plug it into that and if you get a screen then it could be the 2 parts I mentioned or the screen itself. If you can't see the video on the external it's something with the Graphic card which drivers are part of it.
By 'checked the drivers,' I mean updated the current driver, then when that didn't work, deleted the driver completely and reinstalled.
Since then I had to disassemble the laptop for another issue, and I haven't had the glitch happen again. I didn't have to disconnect the screen or cables at all, so I really have no idea what happened. I can't really troubleshoot anymore unless it happens again.
The only thing I can think of is that the GPU was overheating, since there was a little bit of dust around the fan and the heatsink.