PIC24FJ, Connecting AVDD causes Target Device ID of 0x0

Discussion in 'Embedded Systems and Microcontrollers' started by dannybeckett, Jul 20, 2016.

  1. dannybeckett

    Thread Starter Active Member

    Dec 9, 2009
    163
    0
    Something very strange is happening. I connect AVDD to my micro and it doesn't get recognised by Microchip's IPE. When I disconnect AVDD, the correct Target ID is detected and I get the message "Target device PIC24FJ256GB206 found."

    This schematic is correct, as I've prototyped this board before. I've checked all the ground and power pins, and everything seems normal. I've never encountered this behaviour before, does anyone have any suggestion as to why this could be happening? The chip I'm using has been manually de-soldered form a different board, could I have damaged it in a way that causes this error?? Seems strange that it would talk at all if it were irreperably damaged though...

    Any help is greatly appreciated!

    Dan
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,148
    1,791
    Does the chip have a corresponding AGND pin which is floating? For what is probably the 1,000th time: "Why do you think a verbal description is sufficient to help you solve your problem"? Why TF don't you give us SCHEMATICS, SCHEMATICS, SCHEMATICS!!!
     
  3. DickCappels

    Moderator

    Aug 21, 2008
    2,658
    632
    Could it be that the power supply voltage for your PIC is higher than the power supply voltage of your IPE, making the logic levels incompatible?
     
  4. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,392
    1,606
    Define "prototype." is this a PCB where you are very sure the wiring is the same same or is it hand wired where anything goes?

    I try to never reuse desoldered chips, they tend to be troublesome.
     
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