MacBook Pro M3 charger blinking and not charging

Without physically testing it's difficult to say if the problem is the ac adapter or the laptop. If you have access to a different adapter you can see what happens when you connect that. The charging circuit is within the computer itself, not the ac adapter.

Apple provides guidance that includes steps to take if the charge indicator light blinks.

That guidance is here: Charge your MacBook Air or MacBook Pro - Apple Support

❝If the indicator light continues to flash repeatedly, you might need a repair. Get service.❞

You can make a Genius Bar appointment for hardware/software service and support using this link: Contact Apple Support - Apple Support.

Customer Support (800) MY–APPLE (800–692–7753) or on line /getsupport.apple.com/ 

or call AppleCare Support at 1-800-APLCARE (800-275-2273) 

Unplug the power adapter from the electrical outlet for a minute to allow the power adapter's circuitry to reset itself.

If this & @D.I. Johnson's Apple article does not resolve the problem, most likely the issue is with the laptop's Logic Board as @D.I. Johnson mentioned.

In the mean time you may be able to charge the laptop using a USB-C cable instead. If this also does not work, then either your power adapter is bad (rare, but does happen), or the Logic Board on the laptop is bad (more likely).

hejaab wrote:

Hi, I have a MacBook Pro M3 I received it 3 months ago.

The charger all of a sudden is not working it keeps blinking on and off charging for only a moment, am I able to get a replacement charger, I have warranty until 2028

There is a help topic here:

*MagSafe blinking Amber— If your MagSafe cable or power adapter isn't working

Unplug the power adapter from the wall, wait 60 seconds and then plug the adapter back in. This reset the internal electronics of the power adapter. Like wise I would unplug all the cables to reset fro the same reason...

ref: If your MagSafe cable or power adapter isn't working - Apple Support