How to know if my motherboard is dead

[tmwp]

Hello,
I inherited a computer tower from a family member. It had 2 sticks of 256 ram. I added 2 sticks of 512. When I reconnected everything and powered up, there was a slight burning plastic odor. Since then, the computer will power up but my video card does not seem to be working. I replaced it, checked connections, checked the monitor with another computer and I repeatedly receive the error "no video signal". Any thoughts? How would I know if something was burned out on the motherboard? Thanks

 

[iam2thecrowe]

PSU's are the most likely thing to burn out, but you really need to take the covers off and carefully look at the main board for any burnt out chips. no video signal doesnt necessarily mean bad vid card, it could be bad ram, psu, motherboard, cpu, other pci cards..... My bet would be something in the psu is burnt out and the 5v rail is gone letting it power up but no post, or something on the motherboard is fried....

 

[tmwp]

PSU's are the most likely thing to burn out, but you really need to take the covers off and carefully look at the main board for any burnt out chips. no video signal doesnt necessarily mean bad vid card, it could be bad ram, psu, motherboard, cpu, other pci cards..... My bet would be something in the psu is burnt out and the 5v rail is gone letting it power up but no post, or something on the motherboard is fried....

Thanks, I replaced the PSU, tried removing ram and putting in one stick at a time in different slots. I am not sure how to check the main board for burnt out chips or to tell if something is fired. I am no computer expert but have replaced and added parts such as hard drives, cd drives, video cards, memory without issue on previous laptops and desktops. I read online to try removing the cpu battery for 5 minutes and then replace it, which I did, and now no power up of anything other than the LED light. I have considered having it checked out but Staples wants $70 to do a diagnostic assessment and I am not sure it is worth it. Any suggestions?
Thanks