And you bought a new charger why?
Cause if it was due to a charging problem, maybe the issue wasn't in the charger but in the Mac itself. If an SMC reset doesn't cure the problem (only software solution possible), then you will have to take it to a Store or a service provider for assessment.
1. SMC reset
Problems solved: Fans blowing with no activity, machine is not booting, power button pressed and nothing happens, problems with indicators, Magsafe has wrong lights, battery is not charging, monitor and graphics issues etc. If the battery is not charged (from like letting it sleep too long), let the Mac charge up awhile afterwards.
Will not hurt the machine resetting if it's not broken.
Other related hardware problems (optional):
Check battery status: Hold option/alt key down while clicking on the battery icon in the menu bar, top right corner.
Magsafe: Use the correct/matching power supply charger with your Mac, not a less powered one from another Mac.
See if this works for you.
I have a MacBook Pro whose charger suddenly stopped charging (no green light). I read up on resetting the SMC, etc., but to no avail. Here's what happened and how I got the charger working again--admittedly it may be a fluke and I was totally lucky: I was running the Macbook Pro unplugged and I let the MacBook Pro's battery totally run down (I watched various YouTube videos in the last 5% of battery life). Then, as a final try, I connected the MagSafe charger head and the green light came on within a second or two! It's been working since.
In all the other postings for resetting the SMC, there was never any mention of possibly resetting it by letting the battery totally run out of power. So, as I said, maybe my case is a total fluke, but it's certainly worth trying.