Problems with JTAG portion of AVR-USB-JTAG

I have one AVR-USB-JTAG and one AVR-MT128 - both Olimex parts purchased from SparkFun on 5/26/05

Problem I’ve had from the start:

Programming & single-stepping using JTAG work ok, but when “running” with the JTAG connector hooked up the timing is messed up on the AVR-MT128 application - example - blink program to blink the onboard LED (psudo code)

loop1:

wait 1 sec

led on

wait 1 sec

led off

goto loop1

When hooked to the JTAG it is off for 1 second, but only on for 1/10th of a second… when unhooked from the JTAG - works great - 1 sec off, 1 sec on.

Problem I’m having now:

Programming still works well, but the JTAG doesn’t work at all - here are the errors I’m getting when trying to start the debug:

http://www.bc-computing.com/ebay/avrerr.png

Text version:

Loaded objectfile: c:\data\code\avr\avrstudio\osd\osd.obj

JTAG ICE Warning: Reading the program counter, an invalid value (0x7FFFFFFF) was received from the device.

JTAG ICE Warning: A problem occured while executing this debug command! Please check the connections, the voltage, and the clock system of the target application!

Error reading memory IO Address:0 Size:64

Error reading memory REGISTERS Address:0 Size:32

Error reading memory SRAM Address:96 Size:160

Unfortunately I do not have another device to test with to see if it’s the device or the JTAG unit that is to blame…

I’m running AVRStudio V 4.11 SP3, I’ve rebooted, unpowered, etc, numerous times. It stopped working on me last night after working in the morning.

Any ideas?

5 volt regulator onboard the dev board must have an issue - voltage dropped to 4.37 when the AVR-USB-JTAG was connected - powering through the EXT2 connector’s power pins (1 & 2) with a normal 7805 solved all the problems.

Thanks,

Matt