help! new nintendo 3ds power problem

STORY TIME: A few years ago I accidentally bent the card reader's pin because it didn't want to read my Pokemon Omega Ruby gamecard. I thought the reader had some issue so I tried to clean it but I accidentally bent the pins. I must mention that the card reader didn't have any issue to read other games such as Pokemon X or simple DS games, so the conclusion is the Pokemon Omega Ruby got damaged for good. After this I disassembled my 3DS and tried to replace the gamecard reader, I ordered one online but it didn't want to work, so I sent it back, then I ordered another one and the same problem happened. After this I gave up and put it aside the New 3DS for years until today. So I ordered a new gamecard reader and it works, but I have other issues. The console itself doesn't want to turn on, not even the blue light shows up, however, if it is plugged in the charger, and if the orange light lights up then I can turn it on but only with luck. Sometimes the blue light shows up then before the system boots up, it turns off, sometimes I get lucky and the system boots up and the console works for limited time until it shuts off completely randomly. The most I could use it was like 20 mins after I turned it off, sometimes it only works for a few minutes. The second issue is the SD card. If the micro SD card is in, then I get the message that it cannot be accessed. I did format the micro SD card and I even tried with two other different micro SD cards but the problem still stays. The micro SD cards are one 16 gb and two 32 gb cards. I don't think they are damaged because my PC sees them and I can copy files on them. Also I measured my battery's voltage and it gave me 3.75V, so I don't think that the battery is damaged. Is it possible I have problem with the power board? Or is it possible that I have to change out the battery? And what do I do with the micro SD card reader? Does it need to be changed as well?