Compaq backlight don´t works with laptop charger

[amperex]

Hi to all!! I´m new here

I have a strange problem in my compaq 611, it works ok with battery but when I plug the charger the backlight go more bright for an 1 sec and switch off. If I unplug the charger and close down the screen door and open I can see again the screen because the backlight switch on.

Its a very confusing problem because the backlight only goes down when the charger is plugged. If I switch on the computer with the charged plugged I can see compaq logo for less than one second because the backlight switch off.

I opened the screen to try to know if was a problem with the inverter or with the bulb but this laptop screen don´t has a separate inverter like other ones.

Pleaseee I need some helpppp

 

[unksol]

The only think i can think of is that the backlight is turning brighter when you plug in the AC adapter, most do. And you have a problem with the inverter and the additional power draw overloads it. Go into powermanagement and set the screen to the same brighness on AC as when on battery, apply, then plug in the charger and see.

 

[amperex]

The only think i can think of is that the backlight is turning brighter when you plug in the AC adapter, most do. And you have a problem with the inverter and the additional power draw overloads it. Go into powermanagement and set the screen to the same brighness on AC as when on battery, apply, then plug in the charger and see.

If was that the problem I think that will only affect to windows, but I also have the problem when the pc its switch on.

 

[maxwellmelon]

if you have a multimeter carefully check the voltage without shorting out the tip. if the voltage is not reading what is posted on it the power adapter it is bad. im guessing the voltage could be a little high which would shut down the inverter for safety reasons. other components of the computer work off of separate voltage regulators and would be protected from the issue. inverters usually run off of batter voltage directly due to how much voltage they need.