Toshiba L450D new motherboard black screen

kelvin5852 Posts 2 Registration date Saturday August 9, 2014 Status Member Last seen August 10, 2014 - Aug 9, 2014 at 08:28 PM
Ok so a few weeks ago my son's laptop suddenly shut off i took a quick look at it but i couldn't figure out what had happend,so i googled it and had a few attempts at fixing it i.e taking the battery out and holding down the power button but no luck,so i decided to buy a new motherboard for the laptop as it worked out cheaper than buying a new laptop suprisingly,anyway the new motherboard arrived this motherboard had no hdmi output so i guess i got the normal l450d motherboard not the pro, But anyway it still worked and my son was happy until the laptop started freezing,sometimes my son couldn't even get the laptop to stay on for 5minutes before it would start to freeze, Although when using the laptop he was running at least 5 programms at any one time,and the processor is only a amd sempron anyway a couple days later the laptop had refused to show any video on screen,I was puzzled at first because this was a new motherboard i tried a amd athlon x2 but the laptop just turns off after 5seconds..any help?