Black Screen on Boot

[heelsfan951]

I bought a CQ57 339wm to repair. When I got it, it had no screen and no hard drive. I installed Windows 7, then upgraded to 10. After upgrading to 10 I noticed that whenever the laptop went into sleep mode the screen would stay black. If just the monitor had shut down it came back up just fine. I also found that as time went on if I restarted the laptop or shut it down completely it would get the black screen on restart. I have tried hard restarts, different memory modules, different hard drive, a new key board, a new battery. The strange thing is that I have taken the laptop apart several times, all the way to removing the motherboard cmos battery and processor.....and it will start back up after this ....I've done it at lest 3 times and it started back up every time. BUT....when I try to restart it, shut it down or let it go to sleep mode.....then I get the black screen again. Nothing I try will get it to start up correctly except taking it completely apart.

 

[Vince Massi]

Welcome aboard, Tarheels fan (Hah! Thought I didn't know that).

Sometimes this works. When you hit the black screen, press the Ctrl key. Although you can't see it, it will put your prompt on the password line. Then type your password. MAYBE it will let you in.

 

[heelsfan951]

Welcome aboard, Tarheels fan (Hah! Thought I didn't know that).

Sometimes this works. When you hit the black screen, press the Ctrl key. Although you can't see it, it will put your prompt on the password line. Then type your password. MAYBE it will let you in.

Thanks Vince...I tried but no luck.

 

[heelsfan951]

I forgot to mention earlier. When it goes to that black screen the caps lock will give one continuous blink. From what I read, that could mean CPU failure. Well, I tried another CPU and no luck except when I first installed it and started the computer. Once I did a restart to test it...back to the black screen. I also have another laptop..exact model running Windows 10. That one is working perfectly....tried the hard drive from the working one in the bad one and still a black screen.......Now something else is going on. The laptop is starting up when I plug in the charger.....even though I have not pressed the power button. I have a used MB on the way, so maybe that will fix it. I'd just like to know what is causing this.

 

[Saltgrass]

Is the system using the Intel graphics from the processor or another onboard GPU? Have you tried an external monitor?

It may be something like a bad capacitor on the system. Also using a known good power supply and or battery might be a worthwhile test.

There are some other threads about systems not waking up but staying in sleep mode continuously.