Laptop overheating after upgrade

[tourangh]

So last week I made some upgrades to my toshiba C655.
I swapped the HDD for a SSD.
Added 2gb of memory(up to 4gb).
I also swapped the intel celeron cpu for a t8300.

The laptop runs much better, but if I am watching videos(youtube/twitch) the laptop freezes after a while and I have to forcefully shut it off. Is this overheating? What could be the cause if it's overheating? When I took the heatsink off my laptop I noticed it was covering two spots, one was the cpu and the other was the on board video. The onboard video had a thermal pad and I didn't replace it. Would adding thermal paste here help?

 

[jimpz]

I will bet the TDP for the Celeron is lower than that for the t8300, so its drawing more power than it was designed for - overheating. also most OEMs (toshiba, hp, dell, etc) do not necessarily design there laptops for upgradability, potentially, the t8300 is not running 'as designed'. possibly due to bios issues, which couls also cause overheating.