Okay, so long story short I took apart a Toshiba Satellite A135-S4677 to replace the TIM and clean out any dust. I know I put it back together right as I used a guide and this isn't my first time taking a laptop all the way down. Now for some reason, it won't post at all, I can hear everything else spinning up, HDD, disk drive, etc. But it's not posting at all and it isn't beeping like I told it to do when booting. Yes, I checked the video cable, it's plugged in correctly. Are there some special hot keys I should be hitting, or do somewhere along the line I mess it up?