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NI-3101-SIG Serial Ports Failing

The serial ports on my 3101 are failing. Does the 3101 have the same capacitor issue as the other NIs? If so, do you know which cap?

Thanks.

Sent from my SAMSUNG-SGH-I317 using Tapatalk 2

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    regallionregallion Posts: 95
    I've not seen a cap issue on these units, however, I have seen the serial ports fail due to a dodgy power supply. The rest of the controller worked fine - IP comms etc.

    Double check your PSU.
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    TurnipTruckTurnipTruck Posts: 1,485
    Oscilloscope shows just over 13 volts with no ripple or other noise.

    I moved the serial devices to an NI-4100 on the same power supply and they are working normally.

    There is one master power supply that powers many devices. I will try isolating the 3101 on its own supply and see what happens.

    Thanks.
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    Joe HebertJoe Hebert Posts: 2,159
    The serial ports on my 3101 are failing....
    If you measure the voltage between ground (pin 7) and RX (pin 2) it should read somewhere between -3V to -12V when idling.

    I know one of the pins (RX or TX) should idle at the negative voltage; I’m pretty sure it’s RX.

    If you're not getting that then I think it's a sign that the port is dead.
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    HedbergHedberg Posts: 671
    Joe Hebert wrote: »
    If you measure the voltage between ground (pin 7) and RX (pin 2) it should read somewhere between -3V to -12V when idling.

    I know one of the pins (RX or TX) should idle at the negative voltage; I’m pretty sure it’s RX.

    If you're not getting that then I think it's a sign that the port is dead.

    The rs232 spec requires from -5 to -15 vdc. That voltage should appear between the transmit pin (#3 on an AMX DB9) and ground (pin 5). AMX ports that I have measured seem to come out quite well: -9.5 vdc or so.

    Interesting fact: masters with bad caps can still be used either RS422 or RS485. The first of these we encountered had us going for a while because everything but the Sony EVID70 cameras (RS422) quit.
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    Joe HebertJoe Hebert Posts: 2,159
    Hedberg wrote: »
    ground (pin 5)
    Oops, right DB9. I don't know why I was thinking DB25 which is pin 7 for ground.
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    TurnipTruckTurnipTruck Posts: 1,485
    Hedberg wrote: »
    The rs232 spec requires from -5 to -15 vdc. That voltage should appear between the transmit pin (#3 on an AMX DB9) and ground (pin 5). AMX ports that I have measured seem to come out quite well: -9.5 vdc or so.

    Cool. Will test for this today. Thanks.
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    TurnipTruckTurnipTruck Posts: 1,485
    Hedberg wrote: »
    The rs232 spec requires from -5 to -15 vdc. That voltage should appear between the transmit pin (#3 on an AMX DB9) and ground (pin 5).

    In my case I am showing a positive 13 volts between 3 and 5. (Negative test lead on 5)
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    TurnipTruckTurnipTruck Posts: 1,485
    Problem was the cap. In the case of the NI-3101-SIG the cap is C206.

    Picture attached.
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    DHawthorneDHawthorne Posts: 4,584
    Problem was the cap. In the case of the NI-3101-SIG the cap is C206.

    Picture attached.

    At least it looks like an easy one to replace ... though I admit I'm troubled by the trend with AMX masters having caps that dry out.
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    the8thstthe8thst Posts: 470
    DHawthorne wrote: »
    At least it looks like an easy one to replace ... though I admit I'm troubled by the trend with AMX masters having caps that dry out.

    It does seem to be too much of a trend for a manufacture of "Mission Critical Components" not to nip in the bud and put an end to.

    I am sick and tired of selling high dollar "best in class" reliable equipment from manufacturers (not just AMX) that fail, have known firmware issues which exist for years, and simply don't live up to the manufacturers stated features. How many times do I have to say, "Sorry sir. We engineered, planned, installed, and programmed everything the best way possible. But equipment fails and needs to be fixed." or "The manufacturer just discovered a couple problems and they are issuing new firmware to fix it" or "sorry. The product was released with a fully functional firmware, but they will enable those features in a future firmware update".

    It's pathetic. Nothing works, and the installing companies are on the hook for it with zero help from the manufacturers and their under performing QA departments.

    -- rant off, but I don't feel better yet
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    John NagyJohn Nagy Posts: 1,736
    It should be noted that no QA can predict which components will fail prematurely, when "prematurely" is measured in many years after manufacture.
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    viningvining Posts: 4,368
    John Nagy wrote: »
    It should be noted that no QA can predict which components will fail prematurely, when "prematurely" is measured in many years after manufacture.
    Completely agree but I honestly haven't been impressed with anything rolled out in the last 8 years from physical designs and appearance to reliability of the electronics, batteries, lan adapter, touch screen surfaces, etc. Not to mention their screwed up dealer programs and trying to figure out who my new rep for the year is. I don't know if AMX doesn't work well with REPs or if the REPs just don't like dealing with AMX but the North East has gone through around 5 in about as many years. Something somewhere isn't right and if I were to point a finger I think you can imagine where I'd be pointing.
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    John NagyJohn Nagy Posts: 1,736
    I agree overall. The AMX/REP situation particularly has been an embarrassment for years.
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    TurnipTruckTurnipTruck Posts: 1,485
    My NI-3101-SIG was built long after the capacitor problem became evident. The excuse of not knowing that the problem would occur down the road expired long ago.

    For many people (and companies) solving a problem means admitting that there is a problem. Not always so easy to do.
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    TurnipTruckTurnipTruck Posts: 1,485
    Several people sent PMs about this. The picture I posted shows the cap already replaced. The failed cap was a surface-mount type like the others seen in the picture. Having no machinery on hand to deal with surface mount devices, I replaced with a standard, radial lead type capacitor.

    To remove the surface mount one without the proper tooling, gently rock it back and forth perpendicular to its two solder pads. The solder will eventually break and free up the cap. Bend the legs of the new cap into a T-configuration and resolder over the pads. I used a cap rated at 105 degrees Celsius as as added protection against future failure.
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    viningvining Posts: 4,368
    SeveralTo remove the surface mount one without the proper tooling, gently rock it back and forth perpendicular to its two solder pads. The solder will eventually break and free up the cap
    If you pry too hard when rocking the cap the mount will pull off along with the cap and then the nightmare begins. You can scrape off the the poly coating on the foil runs on the - side but it's pretty small and the foil will tear if not careful. I then tried to solder the + side to the eyelet but that eventually just came off so I needed to make a jumper to the other side. Once done I crazy glued the cap to the board since any movement will rip the foil run off the board.

    This was my 3rd time replacing a cap in masters and this time wasn't the charm, the first two were fairly easy but this one really sucked and looks like crap. Fortunately this is now my shop 3100 since I used our 3100 to replace this one to avoid replacing the cap in the field.
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    vining wrote: »
    Completely agree but I honestly haven't been impressed with anything rolled out in the last 8 years from physical designs and appearance to reliability of the electronics, batteries, lan adapter, touch screen surfaces, etc. Not to mention their screwed up dealer programs and trying to figure out who my new rep for the year is. I don't know if AMX doesn't work well with REPs or if the REPs just don't like dealing with AMX but the North East has gone through around 5 in about as many years. Something somewhere isn't right and if I were to point a finger I think you can imagine where I'd be pointing.

    Man, I can't agree with this more especially as far as reliability and QC. AMX doesn't have my confidence these days, that's for sure.
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    DHawthorneDHawthorne Posts: 4,584
    It isn't so much that their quality control is so much worse than anyone else ... they are about on par with competing systems we have used. It's that AMX *used* to be so much better than everyone else.
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    a_riot42a_riot42 Posts: 1,624
    Oh no! Not more capacitor issues! I thought we were done with that. What's next, more expanding battery issues? How many times are we going to have to deal with the same hardware issues over and over? That ain't progress. I take some comfort that I won't be dealing with battery or wireless issues anymore, considering AMX seems to have quit making touch panels that use either feature.
    Paul
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    mushmush Posts: 287
    Please note that there is a more permanent fix to the capacitor issue.
    Replacing the cap with another electrolytic will see the same problem occur again in the future.
    The more permanent fix involves soldering a surface mount resistor and capacitor in series to replace the failed capacitor.
    The faulty cap is C155 in the NI-x000 and early series NI-x100 masters or C206 in later series NI-x100 masters.
    The parts required are;
    • 6.8 Ohm resistor, 1206 package, 0.25W, 5% or less
    • 10uF 50V capacitor. 1210 package, 20% or less
    The resistor is soldered on the positive (+) terminal and the capacitor on the negative (-) terminal.
    The capacitor and resistor are soldered together in a v to allow them to fit between the pads.
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    TurnipTruckTurnipTruck Posts: 1,485
    Thanks for the info.

    Where did you get this fix? I am skeptical. Unless we are dealing with high levels of current, I don't see how 6.8 ohms of resistance would affect the operation of the circuit in question.

    Sent from my SAMSUNG-SGH-I317 using Tapatalk 2
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    mushmush Posts: 287
    Thanks for the info.

    Where did you get this fix? I am skeptical. Unless we are dealing with high levels of current, I don't see how 6.8 ohms of resistance would affect the operation of the circuit in question.

    Sent from my SAMSUNG-SGH-I317 using Tapatalk 2

    No worries.
    I got this from the horses mouth, so to speak.
    I've been using it for some months now and had no issues, too early to tell for long term reliability.
    I think the fact that the electrolytic is replaced with a ceramic is the key. A ceramic can't dry up of course.
    Maybe the resistor is there to change the impedance to suit the remaining circuitry?
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    viningvining Posts: 4,368
    mush wrote: »
    No worries.
    I got this from the horses mouth, so to speak.
    Basically since AMX never issued a TN on this repair procedure or made any recommendations on this forum everyone you ever affected their own repairs only provided their clients with a temporary fix. Hmmm, that's f'd up, thanks AMX!
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