Dell Inspiron 17R 5737 dead after reverse polarity

hello,

i broke my AC adopter and used a similar one with 19.5 V and lower Amp than what was on the original adopter. unfortunately it had reverse polarity and as i plugged it in, my laptop died immediately. 

there was no smell or any thing but it wont turn on anymore. i have replaced the battery and also got a new AC adopter  but nothing works. it's completely dead

will replacing the power supply fix the issue or is the motherboard fried?

i'v searched the internet for a solution, some say just replace the power supply some suggest motherboard components need to be replaced. i'm not sure what to do.

thank you for your assistance.