which is the wrong wirh left half screen is dull in aspire 4750 g

[sharmakss]

What is the problem with aspire 4750 g half screen dull

 

[BadAsAl]

Could be 1 of 3 things:
Bad LCD panel
Bad LCD cable
Bad graphics card

If it shows normal on an external display then it is not the graphics card so try that first.
You can disassemble to the point where you can see the LCD cable and while the laptop is on, you can poke the cable with a non-metallic object (like a plastic pen) and see if it has any effect on the screen. If it does it might just be the cable. If not, then it is most likely the LCD panel itself.
Replacement cable on eBay is less than $20, a screen will run you $50 to $60.

 

[Srijib]

Try connecting to an external monitor or HDMI device. If things looks good the it could me the connector, or LCD itself. Connector is lose. You can unscrew the laptop cover and check these parts.

If external devices also has same effect it will be the GPU. if it is a GPU then you have a tough time. look if you mobo supports external GPU else you have to try heating the GPU to check if it is causing by cracked soldering on the GPU -MoBO connection.

Heating over 230 degree C will melt the connection to rejoin them.( you have to be careful while doing it ) follow youtube video if needed.

 

[Jen_Sai]

It sounds like the lcd panel backlight to me.
Happened to my old lcd tv, the entire bottom right hand corner was a quarter the brightness of the rest of the screen
Our tv was too cheap to to warrant changing the lcd panel but depending on your laptop size/age/model it may not be too expensive.

Check the other things that BadAsAl and Srijib said before ripping out the panel incase it it something else, a simpler fix