My JTAGICE Mk II will no longer successfully connect via JTAG or ISP; it does still work with DebugWire. I have borrowed another JTAGICE Mk II to verify the problem is not with the targets (STK500 w/ATmega32 & custom design w/ATmega168). When connecting with JTAG, the error message is "One or more JTAG lines appear to be stuck..." When connecting by ISP I get a generic error message with a tip to check clock speed.
I installed SP2 for AVR Studio 4 on March 22 and it downloaded new firmware into the JTAGICE Mk II. I now have revision 0x0409 0x0418 while the unit I borrowed has 0x0407 0x0414. (I get a prompt to update the borrowed unit whenever it connects.) Since upgrading the firmware I have been using only DebugWire, so it seems likely the upgrade is the problem. I repeated the upgrade (using the Tools menu) to make sure it wasn't a glitch in the upgrade process.
Is there a way to go back to an earlier version of the firmware? Is anyone else having trouble with this firmware?