Black screen on Toshiba laptop

[octoolguy]

I sure hope somebody can give me some help. I'm pulling all my hair out. I have a Toshiba A55-S306 laptop running a centrino processor. The screen light has gone black. I can hold a flashlight to the screen and see the image so I know it's getting the signal from the motherboard. I replaced the inverter, ccfl and video cable but still no backlight. Can anybody offer another suggestion. I hate to have to pay somebody to fix something that I should be able to fix myself. I have no way of checking the replacement parts to make sure they are good without buying more. I'm stuck. Help.

Ray

 

[denis280]

it could be 2 things. video card or the screen.

 

[C1]

Sounds like the backlite simply is not lighting up. Recommend using a meter to signal trace the power to the inverter and CCFL (eg, is power going into the inverter and coming out?; is the CCFL receiving proper power/voltage supply?). Could be some kind of CCFL section power supply delivery failure from the MB's power supply section.

 

[octoolguy]

Thanks to both of you, C1 do you have any idea of how much voltage I am looking for? 12V D.C.???

Ray

 

[paul878]

Use the Continuity function on a Multi-Meter and test the lcd-cable to make sure it is not broken. Input voltage for the FL-Inverter is 8-20 volts, I don't think you can measure the output with a meter.

 

[octoolguy]

Use the Continuity function on a Multi-Meter and test the lcd-cable to make sure it is not broken. Input voltage for the FL-Inverter is 8-20 volts, I don't think you can measure the output with a meter.

Thanks Paul, I'll give it a try.

Ray