Answer to "Why can't my camcorder recognize the memory card?"Hello, Since you stated you are experiencing problems with your SD card not working properly, it will be useful for you to replace the SD card, as stated here in the guide (Samsung HMX-W200 Troubleshooting).
Answer to "Why my camcorder won't turn on?"Hello, Since you stated you tried to charge your camcorder without any luck, you may have a faulty USB charging port. But do not worry as you can follow the guide here (Samsung HMX-W200 Troubleshooting).