How do I fix backlight and microphone issues on MacBook Pro keyboard after battery change?

Perceff wrote:

I replaced the battery myself. It's an original battery and I don't see how this could be related, given that it was physically impossible to cause any damage.

How does it work that while replacing the battery it is "physically impossible to cause any damage"?

The simple act of opening the chassis is enough opportunity for some damage to happen.

If you are confident in your ability to service the computer, then by all means open it up again and revisit whatever it was that you did. Maybe a connector was left or knocked loose?

Otherwise, this:

Get your Mac repaired and see how much will it cost: Mac Repair & Service - Apple Support 

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

 Call 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) 

Perceff wrote:

replaced their MacBook Pro battery

Mine has started malfunctioning.

About my mac: Macbook Pro 13-inch, 2020, Four Thunderbolt 3 ports macOS: 13.1 (22C65)

[Re-Titled by Moderator]

Original Title: Problems after replacing the battery

What does that mean exactly..." Mine has started malfunctioning." ?

This is unclear—

are you saying immediately after you closed it up and booted the machine the issues presented?

if not directly correlated in this fashion, then I would speculate it is mere coincidence...

and you have a potential hardware issue unrelated to you changing your battery.

On an Intel Mac— you can try all three for software related issues:

—reset the System Management Controller Reset the SMC of your Mac - Apple Support

—reset NVRAM/PRAM Reset NVRAM on your Mac - Apple Support

—A SafeBoot Start up your Mac in safe mode - Apple Support will sort many anomalies

if no resolve: run the User Diagnostics to test your Mac for hardware issues and see if it kicks out an error code. Plug into power when running the test. Use Apple Diagnostics to test your Mac - Apple Support

If you. believe it to be causal, take it back to Apple or the Apple Authorized service center where you had the battery replaced.