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Just fried my homework board — Parallax Forums

Just fried my homework board

CampeckCampeck Posts: 111
edited 2010-09-27 11:23 in BASIC Stamp
oops. The PIC on the board is done for.

went from Vin (15v) directly to ground. Stupid same colored wires.

Anyway can I replace the PIC on the board? or does it need a special code loaded onto it first? Thanks.

Comments

  • CampeckCampeck Posts: 111
    edited 2010-09-18 11:45
    Ok nvm.
    Just ordered a replacement interpreter chip.
    Hope I can fix it. The volt reg seems to be ok. Cant really tell about the eeprom
  • deltabossdeltaboss Posts: 10
    edited 2010-09-18 12:44
    so what happened to it
  • CampeckCampeck Posts: 111
    edited 2010-09-18 13:43
    I was hooking up a relay board to the output of pin15. And went to hook the Vdd of the relay board to Vin of the Basic stamp. But I had the ground wire of the relay board instead. So Vin went right to ground. I would have thought it would fry the relay board but I saw the PIC bubble up and sputter. Oh well.
  • TinkersALotTinkersALot Posts: 535
    edited 2010-09-18 13:54
    so sorry to hear about your wisdom born of pain. If you have a shortage of different color wires, consider some of these ideas to "mark them":

    1. Use a sharpee pen and run a stripe down them to make them visibly different.
    2. Put some tape on the wires to label them as to what they are
  • Spiral_72Spiral_72 Posts: 791
    edited 2010-09-20 11:02
    You know, it's "POSSIBLE" it will still run off 5V...... possible mind you that you ruined the on-board Vreg. Run 5V to the VDD on the BS and see if it programs.
  • CampeckCampeck Posts: 111
    edited 2010-09-20 11:09
    I doubt it. The PIC itself is bubbled and gets scorching hot when power is connected.
  • sylvie369sylvie369 Posts: 1,622
    edited 2010-09-20 11:12
    So you're able to remove the SMT PIC and replace it? That's pretty impressive.

    I'm pretty sure I could install a new one on a bare board, but I wouldn't stand a chance of removing the old one without messing up other stuff.
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2010-09-20 11:23
    It's really not too hard to replace that chip. You can buy the OEM chip as a replacement and solder it on. There are a couple of techniques discussed in this thread:

    http://forums.parallax.com/showthread.php?t=125717

    Robert
  • CampeckCampeck Posts: 111
    edited 2010-09-20 11:56
    Well my work has chipquick, a heat gun, paste flux, and microscope so I should be set!
  • CampeckCampeck Posts: 111
    edited 2010-09-27 09:49
    Well I just had the board repair guy at my work replace the chip and the green power LED won't come on. MCLR is reading .6v and when I put 5v on it the Green LED lights. Maybe something else in the brownout circuit or ICSP is busted? Ideas?
  • ercoerco Posts: 20,257
    edited 2010-09-27 10:20
    In all seriousness, Grilled Homework Board is much healthier for you.
  • CampeckCampeck Posts: 111
    edited 2010-09-27 10:25
    Ok well we just did some troubleshooting and the brownout detector had 65 ohm from vdd to ground and was dropping the voltage on MCLR to .9V. We lifted the detector out of the circuit and now the LED lights. But when I hook the serial cable up I am getting echo but no loopback.
  • CampeckCampeck Posts: 111
    edited 2010-09-27 11:23
    Ok if you press the reset button right when you identify it can see the BS2. but still no loopback. and It wont download. I am pretty sure it must be that brownout detector IC.
    part # S-8054HN
    I can't find it on digikey. anyone know a source?
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