Vaio VPCCW17FX No Backlight

Good afternoon.

I'm repairing a VPCCW17FX for a client. The client's son got a little...violent..went the computer and ended up punching the screen..Not good. So needless to say the screen needed replacing.

Got the replacement screen (After much fuss about side-mounts, top-mounts, etc) and got it replaced--a fairly mundane and routine procedure..

But now I have no backlight.

I realize that this is an LED backlit screen, so I know there's not one single lamp, but rather a series of LEDs.

The screen functions and the machine boots into Windows, I just get no backlight. Display is perfect on an external monitor.

Adjusting the brightness has no effect.

"DISPLAY OFF" button seems to do absolutely nothing.

Anyone have any ideas before I RMA this screen?

 

Do you see the bios screen? If not, then it's definitely hardware. If you can confirm and image on the screen (go out into a bright area with the machine on) it's likely the inverter is bad or not properly connected. The backlight itself is part of the LCD panel.

 

There's no backlight at POST or in the BIOS, or if I boot off of a DOS-based CD. So I'm guessing it is hardware related. Being an LED-backlit screen, the inverter and the screen are permanently connected and there is no way to separate them. There is no ballast or anything of that sort, since it's not a florescent bulb.

There's only one connection from the mainboard to the screen (Directly into the inverter) as opposed to a standard florescent backlight. So it must be a bad LED cluster or something.

I've never worked with replacing an LED-backlit screen, so I really don't know what to expect here.

 

^good point, I haven't replaced an LED backlit panel but I was of the impression that an LED panel still used an inverter...I thought the LED's were high voltage still. There is a very real chance I'm wrong though

Let me ask you this. When you plug in an external monitor, do you see in the display manager the internal lcd (active)? If not, then it could be a connection issue or another issue altogether.

 

Yeah, it shows both screens and will identiy the screens properly as 1 and 2 when told to do so.

There is an inverter, it's just not a detachable inverter. It's soldered permanently to the screen itself and them wrapped in high-temp plastic. They don't want you removing it.

 

Ahhhh ok. I'm assuming you checked the connection there and it's a-ok since you seem to know what you're doing.

Sounds like a bum inverter, and thus a bum panel, sadly.

 

Yeah. Checked the connections at both mainboard and screen-level. Both are well seated and the cables appear to be in-tact and not twisted or frayed in any way.

 

After replacing the LCD for practically same senario (child damged LCD), I have come across the exact same problem with this same model system and did the same troubleshooting as ramp4ge, except I went one step further in replacing the LCD cable as well. Did replacing the LCD a second time get the backlight working for you ramp4ge?