SW CLK pin problem.

franco23 · ‎2011-03-28

Posted on March 28, 2011 at 16:55

SW CLK pin problem.

Tesla DeLorean · ‎2011-05-17

Posted on May 17, 2011 at 14:29

Have you check the current draw on working vs non-working boards?

Do you have any solder shorts?

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franco23 · ‎2011-05-17

Posted on May 17, 2011 at 14:29

Hi,

no shorts on the board.

No visible differences on supply current (with flash erased 10uA less on a total of 2mA on the faulty board).

Note: I attach the SW-DP connector with the micro already powered.

franco23 · ‎2011-05-17

Posted on May 17, 2011 at 14:29

No more ideas?

Thanks.

John F. · ‎2011-05-17

Posted on May 17, 2011 at 14:29

''I have 10 boards, identical each other.'' Obviously you don't.

One board worked when you changed the microcontroller. Did you maybe zap the pins with static? I assume you have no protection on the pins which connect direct to the connector.

If you have no short circuits, then logically, you have damaged parts. Are you sure you don't have two adjacent pins bridged by solder?

The only other option is that your design is marginal and some parts work and some don't. Seems unlikely if the pins connect direct with no intervening circuit.

Swap the microcontroller on a non-working board. While the microcontroller is off the board, check the board for short circuits. Observe anti-static handling precautions. Then ... does it work?