2 Bad Screens, or MB?

I have a Presario F500, and a V2000. The F500 screen flickers then goes dark. You can still see the screen if you put a flashlight on it. The V2000, has lines and a white bar on the right hand side of the screen. Both work fine hooked up to an external monitor. Everything I read seems to point towards bad screens. I just wanted someone elses opinion. Thank you for any help.

 

If both work fine when connected to an external monitor, it is either the screen or the cable that connects the motherboard to it.

The F500 sounds like the LED/LCD lighting has gone bad and the entire screen must be replaced. On the V2000, can you get the screen to display normally by moving the lid up and down? If so, it's likely a bad internal video cable. If not, the screen will have to be replaced.

Hope this helps.

 

I have been reading ont eh F500, and some think that the backlight has gone out. Usually this is a simple inverter swap?

And V2000sounds like a signal issue. It might be the internal cable from the motherboard to the display is bad. Also replaceable with some effort?

Does this sound about right? Thank you again!

 

On most of the notebook screens I've seen, the inverter board is hardwired to the screen. It would be far easier just to replace the whole screen.

 

I replaced the screen today on the F500, and it still went dark on me... I can still see it with a flash light. Whats causing this? Thank you.

 

Dumb_Question
14.July.2013
Compaq Presario S5160UK DT261A under XP/SP3
Processor - Celeron 2.7 GHz
Motherboard - MSI MS-6577 v2.1
RAM - 1GB + 512MB (1GB +1GB max) DDR PC2700
PSU - Octigen 300W model 10270PSOTG ('upgraded' from original Bestec 250W PSU [in 2011?])
Nvidia GeForce 6200 graphics card in AGP slot.

 

If you've replaced the screen then the only component left is the inverter so first make sure you've connected it, there should be two wires going to your panel one at the back with lots of pins and one at the bottom with 2-4 pins they usually connect through the right hand screen hinge.

You can't test an inverter with a multimeter the voltage is too high usually around 2-10,000V high frequency DC but if you can successfully power the inverter up on a bench either with a separate power supply or while it's in the computer you can connect a cheap pc cold cathode tube and see if it lights up.

The other option is to put two pins or wires in the output from the inverter 'while it's powered dwn' , a purple spark should jump 2-3mm gap, it jumps 1mm per 1000V. Obviously be very careful it's high voltage but saying that I've touched a high voltage inverter a couple of times and it just tingles. Turn the inverter on from a distance and don't go near it until it's powered down.

You should see a spark like this, similar to a cooker igniter, if you do it's working fine.

http://www.youtube.com/watch?v=1D9eLipE5h0

Testing with a cold cathode is more complex and more expensive but safer so that's the way to go IMO but you could always just replace the entire inverter board without testing anything and just hope it works, you can probably pick one up one Ebay for the price of cold cathode kit.

http://www.youtube.com/watch?v=vhEGW46uCVc

 

A high voltage is dangerous when also associated with low resistances and/or high currents or large amounts of charge. I am no expert on displays, so I can't comment on the risk of working with live displays. High voltages with small amounts of charge, very small currents, or high internal impedances are 'safe' (cf van der Graaf generator). But personally, I wouldn't like to take the chance with an unknown. As Rikky says be very careful.

Dumb_Question
14.July.2013

 

Replaced the inverter, and it was bright for about 5 seconds...lol I think this thing is done... What's a good idea now? Thank you!

 

Its the backlight? I put on another screen from another laptop brand, and it worked fine. The screen was a little off, I'm sure because its not the right kind. But at least it stayed lit up....

 

Are you sure you've got the right screen? Every single number of the model number has to match or you can run into problems.

There was a thread here recently and one model letter was different, the backlight would only flicker but not work.

If your sure it's the exact right screen I think you've reached the point to consider RMA'ing the replacement screen, don't bother tryna change the backlight it's far too much work and you'll have to spend weeks researching.

 

Yes I pulled the screen out to match #'s with what I ordered. And they sent the same one. At least the stickers matched.

I emailed them and let them know what's going on, and everything I have done to get this working. I would rather not have to put in a backlight, a screen is so much easier...lol Thanks for the help!