My Macbook pro sometimes gets frozen and makes Bip sound for 3 times during reboot

I am using Macbook pro MD101. It recently get laggy and frozen frequently. The screen shows like the following image attached. Each time I shut it down, then open it again, I hear the bip…bip…bip sounds. Sometime the reboot helps, but sometimes I have to leave my Mac for a while, then turn it on gain.
Can someone give me some advises?

Thank you,

This issue must be related to the RAM. Did you replace or upgrade the RAMs?

I upgraded the memory to 8Gb (2x4Gb) using 2 different Brands. One is Hynix and another is Kingmax.

I would recommend change back to the original RAMs. If you want to upgrade, do it in a right way using just one or 2 identical sticks. You may want to take a look on this article: