AT90USBKey Hardware User Guide
AT90USBKey Hardware User Guide
AT90USBKey Hardware User Guide
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Figure 3-1 . Troubleshooting <strong>Guide</strong><br />
Section 3<br />
Troubleshooting <strong>Guide</strong><br />
Problem Reason Solution<br />
The Green “VCC-ON”<br />
LED is not on<br />
AVRUSBKey does not<br />
work<br />
The AT90USB cannot be<br />
programmed<br />
AVR Studio does not<br />
detect the AVR JTAG<br />
ICE.<br />
No power supply<br />
The AVR JTAG ICE<br />
probe is not<br />
connected<br />
The memory lock bits<br />
are programmed<br />
The fuse bits are<br />
wrongly programmed<br />
Can not connect to<br />
USB bootloader<br />
Serial/USB cable is<br />
not connected, or<br />
power is off<br />
PC COM port is in<br />
use<br />
AVR Studio does not<br />
detect COM port.<br />
Verify the power supply source (check<br />
battery charge or USB connection).<br />
Connect the JTAG ICE 10-PIN header to<br />
the correct AVRUSBKey JTAG header<br />
(page 13)<br />
Erase the memory before programming<br />
with JTAG ICE.<br />
Check the fuse bits with JTAG ICE<br />
Force bootloader execution with HWB<br />
under reset.<br />
USB bootloader erased after a JTAG<br />
debugging session: reprogram the USB<br />
bootloader with JTAG.<br />
Connect serial cable to RS232 (STK500 -<br />
AVR ISP) and check power connections<br />
Connect serial cable to USB (JATG ICE<br />
MKII, AVR ISPmkIIl) and check power<br />
connections<br />
Disable other programs that are using<br />
PC COM port.<br />
Change PC COM port<br />
Disable COM port auto-detection in AVR<br />
Studio file menu. Force COM port to<br />
correct COM port<br />
<strong>AT90USBKey</strong> <strong>Hardware</strong> <strong>User</strong> <strong>Guide</strong> 3-15<br />
7627A–AVR–04/06
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