JTAG conn problem - Olimex AVR-P40-USB vs. AVR-JTAG-USB

Case:

Establishing connection between AVR Studio 4.14RC1, 4.15 or /4.16 (on Windows XP Pro SP2) and ATmega162 on AVR-P40-USB via AVR-JTAG-USB.

Connection scheme:

PC (host) ↔ AVR-JTAG-USB ↔ AVR-P40-USB ↔ PC (host)

where both devices are connected to the PC with USB-A/USB-B cables and are respectively interconnected with JTAG 10-wire cable.

Considerations:

  1. pins 4 and 7 of on-board JTAG connector ARE connected to Vcc (4.97V according to my last measurement);

  2. JTAG cable is checked pin-by-pin for wire breaches and proper connection (respectively with the board and with JTAG dongle);

  3. uC external reset upon JTAG connection is turned ON in AVR Studio, in case JTAGEN fuse is not enabled (which is not the case with my brand new uCs);

  4. Restarting the JTAG dongle doesn’t fix anything;

  5. AVR Studio successfuly connects to the JTAG dongle, but the problem seems to be (according to AVR Studio) connection between the board and the dongle;

  6. Just in case - both virtual RS-232 ports are mapped respectively to COM1 and COM2 (w/o any conflict with other virtual or real serial ports).

I’ll appreciate some useful thoughts, thus there is a lapse in mine already…