450 Watts is what came with the kit, it has 8 gig of ram. How would a bad cpu act? Friend of mine hooked his 700 watt to it and didn't get anything out of it. so now I'm thinking its the cpu.
Ok, a bad CPU can vary. If it came with those watts in the kit and your friend's 700 watts still didn't do it. Then we are looking at a serious hardware problem. Try the steps with both the 450 watts and your friend's 700 watts PSU if you can. Also, you should probably do this with your friend. Two people are better than one. Feel free to print this all out. Ok, this is what you do:
Step 1: Remove everything out of your computer case. Find a decent sized wooden table.
Step 2: If your motherboard came with an anti-static mat, place it on the wooden table then your motherboard on top of that. If it didn't then forget about the anti-static mat.
Step 3: Place your motherboard on the wooden table and begin rebuilding your computer. DO NOT take the CPU out or the heat sink out. If you do, then you will need to apply more thermal paste and that would be a waist of time and money. Make sure the heat sink is mounted correctly on top of the CPU.
This is your heat sink:
http://images.highspeedbackbone.net/SKUimages/gallery/large/T925-1519-call04-cba.jpg
A proper mounted heat sink:
http://images.pcworld.com/howto/graphics/125186-2407p128-4b.jpg
Also, if your computer is able to turn on, then your CPU is working.
Quick IMPORTANT Note: Avoid static electricity when rebuilding/transporting the motherboard to the table. When you're rebuilding it on the table I suggest you keep one hand on the wooden table and the other to do the job. So no accidents happen. All it takes is one simple shock and your motherboard is ruined.
Step 4: Once everything is rebuilt on the wooden table, turn it on. You don't need to plugin your keyboard/mouse/speakers. The only thing that needs to be plugged in is the PSU and the monitor obviously. To turn your motherboard on there should be an on board switch.
Somewhere:
http://images.highspeedbackbone.net/SkuImages/gallery/large/B450-0780_vcallout02_or_2177924.jpg
I can't tell from that picture but in the case there isn't bring your case up and plug the led connectors to turn it on.
Step: 5 Hook everything up. Then attempt to power up everything. If the monitor gets a signal, then that means before you just didn't plugin something correctly. I know if you didn't plugin the 4 pin connector on the motherboard, that could very well be it. If you still get no signal then there is a bigger problem here.
Step 6: Power everything off, then remove all RAM. If you hear a beeping noise, don't worry just proceed. If you get a signal then one of your strips of RAM are faulty. You need at least one strip of RAM to run a computer so figure out which one is faulty.
Step 7: If the RAM part doesn't work, then remove everything except for the CPU, heat sink, PSU(Obviously) and GPU. So, remove all RAM and hardrive(s).
If you still have a problem, then there is a problem with either your motherboard, or CPU. Probably more of a chance being your motherboard though, because your computer powers on. I would call tiger direct up and send them all the parts back. I would then either attempt to build another computer or just buy one. That would be up to you. I am sorry that this isn't working out for you though but if you finish all the steps that would be trouble shooting everything for the most part.