My MacBook Pro M3 won't turn on after one month of use

If the Battery was left to drain completely to 0% charge for an extended period of time, then it may be impossible to power on the laptop now. Many times the battery needs to be disconnected before the laptop may power on since the laptop gets stuck trying to charge the depleted battery & also power on the device....it just cannot do it.

Plus there is a very good chance the battery has been damaged from sitting at 0% charge for a time.

To add to the already complex problem I've described.....I have encountered some of my organization's M-series Macs where Magsafe3 charging was not working at all and we had to resort to using a USB-C cable to charge the laptop.....in those cases the Logic Board had failed in regards to Magsafe3 charging.

So in your case there is no way for anyone to know what exactly is wrong with your laptop. Most Apple repair techs don't realize there are a few tricks to try & jump start charging of the battery.....unfortunately with M-series Macs those tricks don't really work since an M-series Mac will not power on without the battery connected unlike the Intel models. I got one M-series laptop to charge & power on, but I don't know if it was due to just disconnecting the battery or if it was my other "trick". No matter what, this requires an experienced tech to disconnect the battery. I have no idea if the tech who looked at your laptop did this, but I would ask them to do so before any parts are replaced.

You can try using a USB-C cable to charge the laptop in place of your Magsafe3 cable.

Lesson to learn: Always keep a Lithium Battery such as the one in your laptop charged between 20% - 80%. If you are not going to use the laptop, then power the laptop down (aka full shutdown & power off) to minimize battery drain. An Apple laptop in sleep mode may take a week or two to drain to 0%, but under some circumstances can drain to 0% in one night. Also, before powering off the laptop to store, make sure to first disconnect all external items including the power adapter before selecting "Shutdown" from the Apple menu. Once the laptop is fully powered off, carefully close the Display Clamshell lid making sure not to touch any key or even the Trackpad or it may power the laptop back on.

Here is an Apple article with details for storing a device with a Lithium Battery (I linked directly to the storage section, so you may want to look over the entire article for other tips & information):

Batteries - Maximizing Performance -- Storing Battery - Apple

Here is another Apple article regarding maintaining battery health:

About battery health management in Mac laptops - Apple Support

<< I don't overcharge my Mac, after full charged, I always removed charging. >>

Don't do that! Your very smart Macintosh computer will NEVER over-charge!

That computer is a battery-CAPABLE device. It is not optimized as a battery-operated device. (It is NOT an iPhone.)

Your computer performs best when connected to AC power, such as the power adapter. It can use the full output of the Power Adapter AND when doing especially challenging work will also freely "borrow" power from the battery. In some cases, even with the power adapter connected, the charged state may decline during very stressful work.

When used only on battery, your computer has no extra cushion of power, and may perform more slowly. However, for ordinary non-stressful tasks this may not be objectionable (possibly not even noticeable.)

In general, you should ALWAYS connect a power source when it is possible to do so, and only run on batteries (which could be somewhat slower) when no power sources are at hand. Modern Macs maintains optimum battery charge levels under program control, and will NEVER over-charge. Activate Battery Health Management and do not spend another moment of your time thinking about charging.

Hi,

Try to take your MacBook Pro to other Apple authorized Service provider or your local retail AppleStore, Genius Bar to be examined your MacBook Pro for a second opinion.

Do not judge its actual condition until you have left it connected to power for many hours, at least overnight.