Brightness flickering - AC plugged in - Lenovo G50-30, Celeron N2830

[pawel123]

Hello,

When the power supply is plugged in, my laptop screen(brightness) flickers - it looks as if every 1/5 of a second the screen changed brightness, say about 2-3% - it is a very subtle change but very visible on a white background. I wonder if it is the fault of the inverter or power supply?
On some forums I read that some users have a problem with switching off "Intel DPST" when the power supply is connected.

[spidey]

Re: Brightness flickering - AC plugged in - Lenovo G50-30, Celeron N2830

is it the original adapter you are using with the laptop?

[pawel123]

Re: Brightness flickering - AC plugged in - Lenovo G50-30, Celeron N2830

The power supply is original. My problem looks very similar to the one in the film:
https://www.youtube.com/watch?v=7Moniwv8ewU

[spidey]

Re: Brightness flickering - AC plugged in - Lenovo G50-30, Celeron N2830

is there a replacement of lvds cable with you to test it ? i would check the power source to see if its fluctating.

[pawel123]

Re: Brightness flickering - AC plugged in - Lenovo G50-30, Celeron N2830

I checked the power supply with a multimeter and the power supply gives the correct voltage. How can I check the stability of the power supply under load? Can I use bulbs connected in parallel, etc.?
By profession I'm a programmer.

[caspian]

Re: Brightness flickering - AC plugged in - Lenovo G50-30, Celeron N2830

how is the flickering using only the battery?

[pawel123]

Re: Brightness flickering - AC plugged in - Lenovo G50-30, Celeron N2830

I see this flickering only when the power supply is connected. On battery power (without ac power supply) the image is displayed correctly.
In the power manager (windows 8) I have set screen brightness at 40% for battery power and ac power supply. The adaptive brightness function and DPST technology are turned off. Perhaps the problem is with the inverter (PWM)?

[caspian]

Re: Brightness flickering - AC plugged in - Lenovo G50-30, Celeron N2830

regardless of brightness level configuration, does brightness of the screen gets lower under battery power compared to AC power?

[pawel123]

Re: Brightness flickering - AC plugged in - Lenovo G50-30, Celeron N2830

regardless of brightness level configuration, does brightness of the screen gets lower under battery power compared to AC power?

After connecting the power supply, the screen is a little brighter (despite the same setting of the brightness of the screen for the power supply and battery - 40%). It is very strange that the screen is slightly brighter when connected to the power supply than on the battery. After connecting the PSU, the screen becomes slightly brighter and then the blinking starts.

[caspian]

Re: Brightness flickering - AC plugged in - Lenovo G50-30, Celeron N2830

If you have got another compatible screen, replace the screen for testing. Otherwise, use an Oscilloscope to discover whether any pin of the screen connector has voltage fluctuation.