Display went black. Which connectors do I replace?

Not sure if this is the right section, but I have a T400 with a black screen and I need your help.

I was spraying cleaning solution on the screen and some of it dripped inside. I removed the front bezel and gently wiped off the excess water that reached the video cable, and the laptop was fine. 4 hours later the display suddenly went black. I plugged an external monitor and it worked fine, but the laptop's screen was still black. So I replaced the LCD with a compatible one to see if the problem is with the LCD itself or the connectors, and I still got the same black screen.

Now that I know it's not the LCD; how do I know which part that needs replacing? I think the problem is with the video cable because that's where the water got onto, but I don't know exactly which parts that I need to replace.

Any advice on how to fix this will be appreciated.

 

I would not do anything quite yet. Store the computer in a dry place. Give it 3-4 days to let the water evaporate. Then try it. I can't guarantee that this will work.

Renee

 

if replacing the LCD didn't work then try replacing the inverter.

 

I replaced the inverter with one from a T500 (it looked similar) and I got the same result - very dark screen that's almost black. Does this mean it's not the inverter? Or do I have to try an inverter with the same part number?

I have deassembled the laptop and everything looks dry as a bone, so I don't think leaving it to dry like Renee suggested would do much.

 

"So I replaced the LCD with a compatible one"

Wait a minute? You've a ready replaced the lcd?

Renee

 

I'm a bit familiar with LCD assembly so I tried two LCDs. I thought it was a problem with the backlight bulb or the backlight plug, but none of the previously working LCD screens worked. So I know it's either the inverter or the video cable, I just need to know which one is the culprit so I can order the replacement part.

Anyone know how to tell if it's really the inverter?

Also, should I rule out motherboard issues if it works with an external monitor?

 

after looking at the T400 and T500 parts lists, each have different part numbers for inverters based on screen size.   unless you swapped in the same part number, chances are the inverter you tried made for an invalid test.

check the LCD cable at the middle sockets where the bluetooth card and inverter card each plug in.   if these sockets were damaged or the LCD cable was damaged, one of the side effects is a black/dark screen depending on the specific damage.

while a working external display doesn't automatically rule out a bad planar (motherboard), it does lend to a considerably lesser possibility.   given what you've described, i would replace the LCD cable and inverter long before i worried about the planar.

of course, i can't guarantee any of the above info without having your system sitting on my desk for personal diagnosis.   but, i'm doing my best here not to send you on a wild goose chase.