Laptop shows no picture

[anthgav]

Hi

I have a Sony Vaio PCG-7134.

 

The laptop shows no picture at all on the display.

It powers on and I can hear the hard drive working but nothing at all on the display.

I have opened it up and checked that all connections are not loose from the screen and the inverter.

I have plugged an external monitor into the VGA port to see if I get a picture, but I get nothing.

I was suspecting the inverter but as I don't get an image on the external monitor I am now suspecting the motherboard.

I have a couple of questions.

 

1) Will all laptops display through the VGA port by default without having to change a setting anywhere, such as the BIOS?

2) Can a broken inverter cause no picture at all?

 

Also I would like some feedback about the best way to diagnose the problem.

 

Thanks.

[KenB]

Hi and welcome to ExTS

 

as I don't get an image on the external monitor

Did you toggle to the monitor using the appropriate Fn + F key?

 

Can a broken inverter cause no picture at all?

If the inverter has gone you normally get a very feint picture that can just about be made out.

It is difficult to determine if "No Picture" is due to a faulty inverter or the backlight itself.

[anthgav]

Thanks for the reply

 

I tried the toggle button Fn & F7 but it did not make the external monitor work, I thought that only worked once windows has loaded and logged on?

 

As i can't get an external picture through the VGA do you think its the motherboard that's causing the problem as opposed to the screen?

[KenB]

Hi,

I thought that only worked once windows has loaded

It does.

 

It powers on and I can hear the hard drive working

I assumed from this that the system was booting - even if you cannot see the final result.

 

I have just re-read this:

have opened it up and checked that all connections are not loose from the screen and the inverter.

If you are doing this again please ensure that you remove the battery and power adapter.

The inverter has approx 19v on the input but significantly more than this on the output.

It could give you a bit of a shock :)

 

If you are getting nothing at all on screen from the VGA - and you cannot see a feint image it looks as if it is motherboard related.

[anthgav]

When I took it apart I made sure there was no power or battery plugged in.

Thanks for the input!

[michelsmith]

Hi,

 

Due to the problems in the inverter or due to the troubles in the cable connection usually screen flickering happens in the display of HP Laptop. As the inverters are responsible to supply power to the back-lit of the screen, any problem in the inverter would create troubles. By replacing your inverter and by checking the connections of the cable in your HP laptop, this problem could be easily resolved.

[KenB]

michaelsmith

 

If you are quoting another person's reply from another forum it is usual to acknowledge the fact.

Your reply above was written by pctech33 on 14 June

You just changed Sony for HP

 

Also - if you read this thread carefully - I suggested that it is likely to be a motherboard problem as an external monitor cannot be used from the VGA port.

Replacing the inverter as you suggest, will not resolve this particular problem if it is motherboard related.

 

We have to be careful what we suggest as a "solution".

What resolved an issue in one thread will not necessarily be the solution on another.

[anthgav]

He didn't even bother to change HP to Sony, lol :)

 

Thanks for the help, I've deemed it as a motherboard fault, I have sourced a fairly cheap second hand motherboard on eBay, thanks.

[KenB]

I have sourced a fairly cheap second hand motherboard

Please be aware:

If the m/b is not EXACTLY the same make and model number as the original you will almost certainly have to reinstall the Operating System.

 

If it is XP and you have the original installation disk ( not recovery disks or OEM ) then you could do a Repair Installation.

 

OEM installations are tied to the original motherboard.

[anthgav]

The motherboard is of exactly the same model number, The licence key sticker says "Windows Vista Home Premium OEMact" and under that it says "Sony Corporation", so looks like I will need the proper recovery disc if I need to re-install.

 

Recovery disc I found this site for recovery disc, my model is VGN-NR38E but the model on the site has an "S" on the end.

[RandyL]

That link says "This is an automated VGN-NR38E S Windows Vista driver restore disk."

 

I don't think that is the full vista restore disk. You might be able to get the disks from Sony but if it's the same mobo you won't need them.

The motherboard is of exactly the same model number

[KenB]

I can confirm what RandyL has said.

 

If the m/board is exactly the same as the old one then all should be well without having to re-install :)