Screen problem i n Dell laptop

[maryam-60]

Hi ,I have seen your commnets.I have problem with the screen too.

My labtop is VOSTRO 1500.The screen is working normaly during the boots and the first part of windows when it asks for the pass word.Then the back light goes off!!

You can still see that the computer is working in the dark screen!But if the problem is back light inverter then why it is working ins the first few moments!!

Thanks
Maryam

 

[americanbrian]

An invertor works by allowing a large starting current to "ignite" (fluoresce) the CCFL. However, once it has started the current would run away and blow the light if it were maintained. So it starts with high current then drops to a low one.

So when you start up it is providing the "flash" of current to start the CCFL, but then it is not maintaining the correct current to keep the fluorescence going...

 

[maryam-60]

An invertor works by allowing a large starting current to "ignite" (fluoresce) the CCFL. However, once it has started the current would run away and blow the light if it were maintained. So it starts with high current then drops to a low one.

So when you start up it is providing the "flash" of current to start the CCFL, but then it is not maintaining the correct current to keep the fluorescence going...

Thanks for your answer.So you think the inverter problem and has to be changed?!!Is that easy to buy in amazon?!easy to to change?
thanks

 

[americanbrian]

I cannot say 100% that the inverter is actually the fault. It could be that the electrodes inside the CCFL have worn away (which is how fluorescent bulbs tend to fail most of the time).

In that case the reason it isn't maintaining the correct current is that an additional resistance is added to the circuit due to the bad electrodes.

In general it is cheaper to replace the inverter first. I would look on EBAY for a model specific one. They are usually no more difficult to change than removing the screen bezel and disconnecting the small molex connector and removing a single screw.

This is from my experience replacing broken laptop screens check youtube for how to videos. They are normally pretty good.

 

[jarotech]

I don't think it is the inverter, to be sure try if you could, plug an external monitor to see if windows load all together.

 

[americanbrian]

^^ if you read the OP windows does load. it is only the backlight of the screen that turns itself off.

so that leaves the screen itself or the inverter at fault.

As I mentioned the invertor tends to cost £10-£25 on ebay in the uk anyway, with replacement screens about 4x that.

it is cheaper to replace the inverter then the screen, but if that fails then it costs more to do both. however if it is the inverter at fault then you have wasted 4x as much money on a extra screen..