Solved Laptop screen won't come on.

[Amacey]

Right so now I have replace the DC jack and the screen still doesn't come on. What else can I try? Thanks!

I have replaced every part instead of the screen and the processor.

I have tried with an external screen however which also displays blank. So could is be a broken processor? Cheers!

 

[vic46]

What about the cmos battery

 

[Amacey]

Not tried anything with the cmos battery yet. What should I do to it? Also not sure what to do about the BIOS since I cant see anything on the screen.

 

[vic46]

just replace battery with a new one

 

[Amacey]

Well ive replaced the motherboard so that has replaced the battery. So not sure I need to replace that i think?

 

[mohavepc]

Amacey:
Have you tried with a different power supply yet?
What about the steps I lined out earlier?
1) no drives cd/dvd or hard drives
2) no memory or minimal and or different sticks if possible.
3) no keyboard (just unplug the ribbon cable)
4) no battery (not Cmos battery just the laptop main battery leave the cmos battery in for now)
5) different power adapter if possible

Removing the cmos battery will reset any user defined settings in the bios including date and time. battery must be removed for a length of time (1 to 10 minutes) to clear the clock. I don't think this is an issue for you to be concerned with as you noted the motherboard has been replaced. It is possible we are barking up the wrong tree here and the inverter or lcd is bad but after reading through this post again the sheer fact that there are no beeps, a whirring noise(dvd, hard drive or fan make those sounds) and still not posting (no beeps or curser on the screen tells us this) it seems something not already changed is at fault. My bet would be on Hard drive or memory. try each mem stick one at a time to see if it changes anything. we have ruled out dc jack, motherboard so far.

let me know if the list above makes any noticeable difference.

 

[Jacee]

Did you say you've tried a new Power AC (or DC) adaptor?

 

[Amacey]

I have currently tried and replaced the following:
+ DC Jack
+ Motherboard
+ HDD
+ Screen VGA Cable
+ RAM
+ Power Adapter

I have just purchased a new inverter which I will wait to arrive and then fit and let you all know. Should I buy a new power adapter and CPU? Thanks!

OH and btw yes I've done all them steps you mentioned but its had no effect

 

[mohavepc]

Since I don't know how you handled the cpu (as in antistatic wriststrap and such) I am unable to answer about the cpu.
The power adapter should have an output of 19 volts (pretty standard these days) Look at the adapter itself and it will tell you what voltage. I would take a multimeter and check the voltage at the tip that goes into the dc jack. you can also use the multimeter on the leads that go into the main battery to see if the adapter is pushing power to the charge and power circuit. I have seen the issue where a power adapter shows full voltage until it goes under a load (plugged into a laptop and powered on) then the voltage drops to near nothing.

The inverter is most likely not the issue as you tested the screen with a torch (flashlight for us Americans) and found nothing visible. if the inverter goes out the lcd will still work just the backlight fails to light up.

you said above that you replaced the power adapter? did you replace the Power adaptor or the dc jack?
I also noted that you said the hard drive light comes on for a second then goes off. is this with the hard drive and dvd drive out as well?

 

[Jacee]

Should I buy a new power adapter

This has me confused ..... did or did you not try a new power adapter? Mine is an AC (in the U.S.), but your's could be DC

 

[Amacey]

Right sorry for the confusion. I have tested both a new power adapter and dc socket.

When I take the HDD out the light doesn't flash at all for the HDD.

If changing the inverter does not fix the issue I will buy a new CPU and power adapter and go from there I think.

Yes the power adapter says 19v on it.

 

[Amacey]

Fixed it! Changed the RAM to new modules again and it worked.

 

[mohavepc]

wow after all that the ram? I thought you already tested or changed it? My bad, that should have been one of the first things I suggested. Glad you got it going.

 

[Amacey]

I did change the RAM. Then read online someone saying it was definatly RAM so brought a second set of RAM and that worked. Must have just been unlucky with the first set.

 

[mohavepc]

Glad it worked, sometimes luck definitely plays a part. Please mark this solved. Have a good day.