Serial Port Hang when send g-code from Pronterface and Reptier Host

I am using Arduino with RAMPS board for my Prusa 3D Printer. I used windows 7 professional as my OS and I managed to upload the Marlin v6 firmware to the arduino board. Following which, I connected only the power source, X and Y motor to the RAMPS. I tried both the Repetier Host 1.06 and Pronterface to move the Y-axis and X-axis by 1mm just to test the connection. I was able to send the first 2 command successfully but after that, the software stop to respond to any commands to move the X or Y-axis. The number of commands waiting also start to pile up. When I restart the software, and replugin the USB port, Windows gave me this error : "One of the USB devices attached to this computer has malfunctioned and Windows does not recognize it. For assistance in solving this problem, click this message". I will need to restart the computer in order for windows to recognize the connection again.

I tried using putty to send g-code and the same thing happens. After typing the 3rd g-code command, an error "Error writing to serial port" pops up. I am suspecting that there is a buffer overflow or somehow the connection is working poorly. It used to work properly before but recently it suddenly started to behave in this manner. Any suggestions on what I can do to fix this ?

problem

Quote
chenjennhaur
Windows gave me this error : "One of the USB devices attached to this computer has malfunctioned and Windows does not recognize it. For assistance in solving this problem, click this message"

fix: restart your usbport. either by skript o by ataching and detaching a standart device(like your mouse). spezial for ramps/pronterface: 1.plug off usb. 2.disconnect pronterface 3. poweroff printer 4. plugin usb 5. connect.6 power on

the Marlin v6 firmware? canyou provide a link pls

have you tried something esay with the arduino? like the blink demo? just to get shure ist not the hardware

Thanks for the advise! Following your sequence of unplugging helped to reduce the USB port error. However, I still have the problem of command delay. i.e. it takes maybe 3-5 seconds after i press the manual control on the pronterface before the y/x-axis actually move.

I have uploaded the blink demo to the arduino and it worked properly
This is the link of the marlin firmware that I am using : [drive.google.com]

Could this problem due to poor wire connections or insufficient power ?