hi please help to fix my mac book pro blinking question mark when I plug in

Okay... manorjan, do the basics first

One: reset the SMC/PMU

two : zap the pram at least three or four times

three : get a Legit DVD copy of the Mac OS. If you don’t know what version of the mac os u have on your MacBook, go with snow leopard dvd( 10.6.3) . You will also need a working DVD drive in your MacBook. If you had/have any DVDs that came with your MacBook 2011, you could try those.If you had access to a spare mac and a usb stick you could make a bootable macOS installer I would suggest El Capitan irMojave.. Try recovering from recovery partition On your MacBook, assuming you have Lion (10.7.5) or later installed on there already... anyways try the recovery partition thing out after you have done steps one and two. If you don’t know how, Apple support page and notebooks will tell you how. You may have Internet recovery but I am not sure on that. To make a bootable USB stick you need an application for that which I can’t tell you here but you can find on the Internet. Just look for bootable macOS USB stick application. There is also a slim chance your hard drive might not be working right. Once u have made the bootable USB stick shut down your Mac and plug the stick in. Restart your Mac and hold down the option key on the keyboard, the usb stick . ThenUSB stick Should be erased and formatted as follows: mac os journal and make boot drive.. you can start from the CD DVD drive by restarting and holding down the C key on the keyboard and inserting the CD into the drive face up...p

johnb

I will try, manorjan. That blinking question mark (?) means that your Mac cannot find a valid OS to boot from. I don’t know exactly what model of MacBook Pro or what year it was made, but if it’s a pretty recent one, it should have a recovery partition on it. To access that shut down your MacBook Pro and restart, holding down the Apple and R keys together.. until you see a language selection screen pick one and continue. From there you can reinstall the OS and do a number of things.

john b