tonysnail Posted December 1, 2009 Report Share Posted December 1, 2009 Hi all.. Whilst going through the MIDI troubleshoot guide, I was probing the chip with an LED.. (Maybe this wasn't a good idea?) I tried to connect the LED wires to Rx(26) and Vss(31) - but the wire touched both Vss(31) and Vdd(30) - causing a tiny spark on the PIC leg, and making the LCD screen turn off and on again.. The LCD was blank before (I tried twiddling the contrast/brightness pots, with no joy) - and it's blank again).. could it be possible that I fried my PIC by doing this? Cheers all! Quote Link to comment Share on other sites More sharing options...
philetaylor Posted December 1, 2009 Report Share Posted December 1, 2009 I would say not very fragile at all. I have done some "really" stupid things to PICs in the past. Installed them the wrong way round, shorted out pins and generally abused them and everytime they just work! Are you getting the upload request MIDI message? If so your PIC is still alive. Cheers Phil Quote Link to comment Share on other sites More sharing options...
nILS Posted December 2, 2009 Report Share Posted December 2, 2009 could it be possible that I fried my PIC by doing this? Yes. A lot of stuff is possible, but just like phil has, I've done some pretty incredibly stupid things to PICs over the last years and never ever managed to actually kill one :-) They're like little tanks with lotsa legs. Quote Link to comment Share on other sites More sharing options...
Enth Posted December 2, 2009 Report Share Posted December 2, 2009 I've broken one... went against my multimeter and "let's see if this works regardless". Quote Link to comment Share on other sites More sharing options...
nILS Posted December 2, 2009 Report Share Posted December 2, 2009 Ubervoltage is a relatively reliable way to kill them. Although I've accidentally powered one with 9VAC for a while until I realised I had mixed up J1 and J2 :) This one still works as well. Voodoo. Quote Link to comment Share on other sites More sharing options...
lylehaze Posted December 2, 2009 Report Share Posted December 2, 2009 Ubervoltage is a relatively reliable way to kill them. Although I've accidentally powered one with 9VAC for a while until I realised I had mixed up J1 and J2 :) This one still works as well. Voodoo. Yes, too much voltage, or Reversed voltage, are top contenders for PIC damage. There are diodes built in that will _try_ to protect the chip, but there are limits.. This is the biggest argument against using a PC power supply to power your projects. Having regulated five volts handy is nice, but forty amps worth will make little mistakes much more colorful. :) Maybe I should sell fast-blow fuses for a living. Getting back to the OP, it sounds like you shorted the power supply, but most likely the power path did not go through the PIC.. If that's the case, check your power supply out and proceed if it's still working.. repair or replace it if it's not. Once you have good power back on the PIC chip, check for the wakeup SysEx string and you'll know if the heart is beating. LyleHaze Quote Link to comment Share on other sites More sharing options...
Schrittmacher Posted December 2, 2009 Report Share Posted December 2, 2009 Ask Polykobol for this! :-) He has a lot of Expirience with damgaging PIC´s. LOL Sorry Francois, but this must be it. :-) Quote Link to comment Share on other sites More sharing options...
Nasrudin Posted December 3, 2009 Report Share Posted December 3, 2009 i fried one too by wrong interconnection between pic and Display. Both, the lcd and the microchip were broken afterwards.. Quote Link to comment Share on other sites More sharing options...
TheAncientOne Posted December 3, 2009 Report Share Posted December 3, 2009 If you are doing the LED probe trick ALWAYS put a resistor in series with the LED to limit the current. If you use a very bright red LED,then 1K is good. Otherwise you always risk drawing too much current from the pin of the chip. Whilst on the subject, it's worth remembering that when driving LED's from a chip, that there is a maximum current that can be drawn or pulled from the package, (the common terminal being the VCC or ground pin). For example 74HC595 used in a DOUT: you can draw 20mA per pin on the outputs, but the maximum Ground or VCC pin current is only 70mA, so the total draw must be less that this. If driving LED's then 8mA per LED is about the max, unless they can never all be on at once. Quote Link to comment Share on other sites More sharing options...
arumblack Posted December 18, 2009 Report Share Posted December 18, 2009 I put one in backwards once and if I hadn't put a label on it to ID it, I would not have noticed.....But the label started smoking and getting a black circle (where the processor die was no doubt). I thought it was dead for sure, but Swapped it around and it booted up.....Not sure if I will trust it though, It's sitting in a box B/C I had extra's and decided to just use a new one to be sure I'd have no problems. Anyway +1 for pics being tough little things... Quote Link to comment Share on other sites More sharing options...
Smithy Posted December 19, 2009 Report Share Posted December 19, 2009 Hehe, anyone for PIC tennis? After 1000 volleys, i bet the things would still work! Quote Link to comment Share on other sites More sharing options...
Polykobol Posted February 5, 2010 Report Share Posted February 5, 2010 Ask Polykobol for this! :-) He has a lot of Expirience with damgaging PIC´s. LOL Sorry Francois, but this must be it. :-) True! Well,I connect a lot of instrument...And, if there is a bad midi galvanic isolation, you burn them. I distroyed 3 PICs using my midibox CV connected to my RSF kobol Modular. C.U. Marko! Quote Link to comment Share on other sites More sharing options...
Snoozr Posted February 6, 2010 Report Share Posted February 6, 2010 I managed to mess up 3 by connecting pins 8 and 28 as compared to 8 and 27. It was a slightly expensive way to find out my fine motor skills aren't what they used to be :whistle: Quote Link to comment Share on other sites More sharing options...
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