I2C error counter question

Discussion in 'Cinestar 8' started by Dave King, Jan 24, 2013.

  1. Gary Haynes

    Gary Haynes Administrator
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    Dave one other item to check is the way the PDB is secured with the screw holes. Looks like you put some grommets under the nuts. Good idea but just make sure that they haven't knocked off one of the small IC chips. That has happened in the past when using just the nuts. Hoping that changing the contact point for the CD connection clears it up.
     
  2. Dave King

    Dave King Well-Known Member

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    I"ll add it to the list tonight to check.

    thanks
     
  3. Dave King

    Dave King Well-Known Member

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    Update: I removed both the C&D wiring at ESC 4, and the (+) (-) connections on the flight control board that I used to hard wire to the PDB. This means the copter is now completely stock and unmodified. I retested, same thing no change. I reflashed the FCB, and it set the IC error counter back to 0 like it normally does. I then unplugged the lipo, plugged back in, the problem still there, no change
    flightcontrol1.jpg

    I have removed the flight control board, and the PDB board and inspected closely. I can't find any irregularities. All the caps look good, all the legs of the caps are intact. None of the caps look over heated. I don't see any small blob of solder that might have gotten onto somewhere it shouldn't have. On the FCB everything looks good except that there is a manufacturing error when they made the board. You can see that the solder pad for the ground connection has a extra little pad underneth it. I noticed it when I first assembled the C8 but I was very careful to solder the wires so that they didn't short together. "The smoke would come out of the wires" as a certain English gentleman would say if there was a short there. See attached pics. Other than that, I am completely dumbfounded. Only thing I can think of is that there is another defect on the FCB or a failure on the PDB that I can't see.
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Nah. Not buying the "too lazy to wire-up things properly" line. Based on everything you've tried I'm itching to swap out the FC and NC one by one just to see which board is causing the problem....

    Andy.
     
  5. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    There's a linear blob of solder between the Gnd and the +5 pads, Dave. Don't think that's the cause of the I2C errors, but it worries me smoke-wires-wise. :)

    Andyl.
     
  6. Gary Haynes

    Gary Haynes Administrator
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    Dave

    There are a good set of bench testing instructions during the build phase over at http://www.mikrokopter.us/index.php?page=7 courtesy of Ziggy. Take it from the top and see what you get. Basically disassemble it all and bring it back together a step at a time. When I did my first build I printed out Ziggy's list and then as I went through it I checked marked each item, like a flight checklist.
     
  7. Dave King

    Dave King Well-Known Member

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    Update: I took the FCB to work today for further inspeciton. I removed all the solder from the connections and cleaned the board. I see some really bad stuff going on here, no sure if its causing these problems but it apears that this board's copper is spreading after its been heated up. As you can see from the arrows it's not good. I have been an electronic tech since 1990 and I am can solder fairly well. I have never seen the copper of the board spread off the board like this. Now we all make soldering mistakes and I am certainly willing to say that I really don't think I did anything wrong here. The 5v pad is almosts gone but yet there was plenty of pad and solder on it yesterday when I removed the wiring last night. Could I have kept the iron on it too long? I usually never stay on a pad longer than 2 seconds "max" at a temp of 650 degrees. It still doesn't explain all the run off of the copper.

    This is the board this past December when I installed the CS8.
    flightcontrol1.jpg

    This is the board this morning
    flightcontrol3.jpg

    Here's a close up of the board this morning
    flightcontrol5.jpg

    flightcontrol6.jpg
    Here's the solder station I used for soldering this board I always use a temperature of about 650. I only go higher for surface mount stuff like the PC extension board.

    solder station.jpg

    Here's the solder I used it's, here's the specs: Kester Sn60Pb40, .031 inches, Flux-Cored Solder Wire, Kester 44 rosin flux. An outstanding performance feature of this flux is the in.instant-actionin. wetting behavior.

    solder.jpg

    Defective board?
     
  8. Gary Haynes

    Gary Haynes Administrator
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    Dave I don't think it is a defective board. I lost a pad replacing a Traco, to much heat as I struggled to to remove solder. And having been on multiple forums over the last 18 months and can't remember hearing of any issue with pads lifting off. You should order a new board.
     
  9. Dave King

    Dave King Well-Known Member

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    I can accept that I could have lifted the pad but what about all the other issues on the board that I pointed out. This board did not look right back in December. Thoughts?
     
  10. Gary Haynes

    Gary Haynes Administrator
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    Dave if the first photo that is labeled as December in post #47 was the board when it was new and uninstalled and it had the big blob of solder on the negative pad, the copper was missing from the PPM, +5 and GN pads then my thought would be that you were sent a used board in your kit.

    You also might want to check the actual temp from your soldering iron. Tip temperature, as I understand from other postings, is a factor of the power to the iron and tip size. So one setting with different sized tips may actually be different temps. Not sure how you could check actual tip temps. This is probably one of the reasons that newer stations are digital for a bit better accuracy.
     
  11. Dave King

    Dave King Well-Known Member

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    The board was new but I had started to solder it when I saw the extra little bit of solder pad under the ground pad. I put the blob of solder on the big negative post. The only thing wrong with the board when I received it had the extra little bit under the ground pad. I believe its a manufacturing flaw not a used board.
     
  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Dave, I think Gary's correct, though....all signs are pointing to replacing the board, I'm afraid. I realize the expense is not welcomed, but, if it turns out not to the be the board, you will at least have a backup board (that's at least how I rationalized getting a second FC, NC, GPS, and PDB, with a couple of BL-Ctrls as well).

    I infer that you bought it from QC, so I'd give them a call.

    Hope this helps
    Andy.
     
  13. Dave King

    Dave King Well-Known Member

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    I talked to Adam yesterday and sent out both boards to Quadrocopter last night. They will have both boards Friday and they willl test them. I left the pigtails on the PDB so they can simulate my wiring too. I have no problems replacing one of the boards at my cost if I knew that I did something wrong or that the hardwiring of the IC2 mod caused something. I do see the value in spare parts now. I seriously doubt that the IC2 hardwire mod did anything because this was the way MK used to wire the boards (they just simplified it). I have soldered a million miles of solder wire in 20 years and I have made my fair share of mistakes, but I have never had solder pads react like this in the way that the copper spills off the pads like this. It's just not solder that has spilled over, its the copper that can't be removed. I have soldered a ton of components and PC boards at the same 650 degrees so I know the temp of the tip is good and not too hot.

    If anything I should have had a solid base line before doing any modifications. I just didn't know anything about IC2 errors to have checked it when I did my initial tests or I would have monitored it from the beginning so I have no real baseline if the boards were like this from the first power up or not. I just assumed that when I saw "NO errors" on the main LED display in MK tools that meant "NO ERRORS". It's a bit deceiving to inexperienced users. Andy maybe you might want to have a little introduction about IC2 errors in the new MK tools video and how you can't necessarily rest if you see the main "NO ERRORS" message. All in the learning process though for me though at least I know now!! Plus on the positive side I caught the problem before it resulted in any type of crash which demonstrates why its important to thorough review the GPX logs.
     
  14. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Good thought, Dave.
    Unfortunately, I'm not sure the production schedule for the DVDs will allow me to add that section for this first version, but point well taken.

    Andy.
     
  15. Dave King

    Dave King Well-Known Member

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    Update: Riley from Quadrocopter tested both my FCB and PDB. He found a very very very small strand between one of the C/D connections on the PDB that was just enough to trigger the error on initialization. So that's a big relief. He also mentioned that he had a board with the same symptoms by a very small strand. I think its time to invest in a good magnifying glass with a light for my bench. The flight control board tests good and he thinks its ok to reuse. I bought another board for the main board and I will keep this FCB for a spare test board. An interesting thing Riley told me was he said Quadrocopter recommends not to use a solder sucker. I usually use a combination of the two depending upon on much I need to remove. So I'll have my boards back in a few days and all is good. Special thanks to the guys at Quadrocopter for great service and support!!!
     
  16. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Solder suckers are pretty aggressive. Desoldering braid is the way to go. :)

    Andy.
     
  17. Adam Paugh

    Adam Paugh Distributor

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    Hey Guys,

    It is pretty remarkable that we were around the world and back again on this issue all due to a microscopic solder bridge. So what did we learn? Yes, a good magnifying glass is a good bench tool. I would also recommend a bottle of isopropyl and a small brush (not too aggressive). When you are all finished with your soldering then a quick cleaning with the solvent and brush will remove any stray pieces of wire or solder.

    In this case the solder bridge was so fine that we were able to flick it off with a fingernail. Be aware that aggressive scrubbing with a brush can dislodge some of the small SMD components (resistors and diodes) on the ESCs.

    Greetings,
    Adam
     
  18. Dave King

    Dave King Well-Known Member

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    I have a good repair bench with tools and cleaning materials just no magnifying glass with a light. You can bet that will be rectified very quickly. Lesson I learned from this is that you never start modifying until you have a good baseline and that you should know what the hell you are doing first!!! LOL!! Live and learn. I think a tooth brush would be pretty good for the components on the PDB and like you mention a good cleaning goes a long way!!
     
  19. Ali Salih AK

    Ali Salih AK New Member

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    Hello ,

    I have the same problem now, and try to solve it :)))
     
  20. Dave King

    Dave King Well-Known Member

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    So your error count doesn't go up at all during run time? Look at all your C & D connections on both the power distribution board and the fly control board.
     

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