No USB detection.

OK. I am building my case for MD, so for the first time everything is connected (jacks, LCD, buttons). Since yesterday, my MD is not detected by any of my pcs. Things I tried:
1) Changed the USB cable
2) Changed the PIC 18F2450 with a 18F2550
3) Disconnected everything (jacks, buttons, LCD) in case the USB port power wasn't enough
4) Tested MD in 2 pcs
5) Reseted to default settings
The strange thing is that MD seems to work great. I mean, the VU on LCD works great everytime I hit a pad. But it doesn't show up to PC, not even as an unrecognized device. I have the latest firmware for Atmega, Synthex 2.5 board with pulldown resistor etc. I would love to have a midi synth around me to test the midi ports, but I don't. Any suggestions?
Problem Solved!!! One of the data cables going from the board to the usb socket was loose. Please lock this one Dmitri...
1) Changed the USB cable
2) Changed the PIC 18F2450 with a 18F2550
3) Disconnected everything (jacks, buttons, LCD) in case the USB port power wasn't enough
4) Tested MD in 2 pcs
5) Reseted to default settings
The strange thing is that MD seems to work great. I mean, the VU on LCD works great everytime I hit a pad. But it doesn't show up to PC, not even as an unrecognized device. I have the latest firmware for Atmega, Synthex 2.5 board with pulldown resistor etc. I would love to have a midi synth around me to test the midi ports, but I don't. Any suggestions?
Problem Solved!!! One of the data cables going from the board to the usb socket was loose. Please lock this one Dmitri...