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Let The Smoke Out of Medallion Power Module...

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    Let The Smoke Out of Medallion Power Module...

    I know this is probably more suitably posted to Electrical, but this area draws the most traffic...

    The backstory is that I last used the boat two weeks ago, returned from the lake, unpacked, plugged in tender, covered and done. It has rained a fair bit over the past couple of weeks, so it has sat covered in the driveway since.

    Last night, I hooked it up, unplugged the tender and drove to get fuel. At several points along the trip, the bilge pump kicked in and drained water that had accumulated in the bilge from the rain - nothing excessive.

    This morning, I went about prepping to hit the lake for the day. Per usual practice, I run through a pre-leaving check by turning on the batteries and Tige Touch to make sure everything checks out. I did turn on the batteries and returned to the helm. At this point, I heard a faint crackling noise of sorts from under the dash and started to notice a smell. I proceeded to power up the touch, but by that point, it was already too late. Smoke was puffing out from behind the electronics access panel. I powered everything down as quickly as I could and opened it up. the pictures below are what I found.





    From the looks of it, the issue seems focused around a couple of transistors (?) near the lower center of the picture. Along with this, the fuses for nav and anchor lights were blown and for all four ballast drain pumps. The auxiliary fuse for the blower was also popped (off the emergency switch panel), but not the one on the Medallion board. Everything connected through the auxiliary panel works - blower too with a replaced fuse.

    I'm at a complete loss as to what caused this - short, bad power module, other? I'm troubled that the issue happened on application of battery power, and before any outputs or systems were activated, including Tige Touch. This leads me to be suspect of the board itself.

    All said, any insight from the community is most appreciated. Thanks.
    2013 RZ2 with Convex VX, MLA Custom Sacs

    #2
    In case it matters, I also measured the battery voltage at the main connections to be 12.72V...
    2013 RZ2 with Convex VX, MLA Custom Sacs

    Comment


      #3
      I had similar problems but higher up on the board is where it started. Tige sent me out a new medallion box and all has been good for over 150 hours since.

      Sorry about your misfortune.

      Comment


        #4
        Originally posted by Travism View Post
        I had similar problems but higher up on the board is where it started. Tige sent me out a new medallion box and all has been good for over 150 hours since.

        Sorry about your misfortune.
        Thanks for that information. I've been trying to contact Medallion all morning with no luck (not at all a new issue...). When my dealer opens for business, I'll see about getting a new board.
        2013 RZ2 with Convex VX, MLA Custom Sacs

        Comment


          #5
          A few comments:

          * It looks to me like the source of the problem is the right hand TO-packaged device at the bottom of the board, next to identical device Q9. That is almost undoubtedly a motor driver IC, put into a TO package because it includes a heat sink tab that is then wavesoldered to the board at the top of the device.

          * The labeling on both of those devices has been burned away, so we can't tell exactly what part number it is. But most of these are based on H-bridges, which make it possible to drive a motor in either direction. Since this is an integrated device (and not a pair of relays), the H-bridge is constructed with transistors, most likely FET's.

          * Some H-bridge configurations have a potentially fatal flaw. If they turn on the wrong pair of transistors, they will have a direct short from power to ground - through an intentionally low resistance path in the device, which means lots of current flow, which means things get hot FAST, with the results as shown.

          This almost certainly did not occur due to an external event such as a bad pump motor, or shorted wires, etc. Most motor controllers detect external overcurrent conditions and handle them because they expect them. But the device doesn't expect an INTERNAL overcurrent situation, so they might not bother using the die area to incorporate sensing for it.

          I suspect that device either just failed, or was somehow commanded to turn on the wrong transistors together. It got hot enough to actually flame. That's a massive problem especially in a marine environment. You could have easily had an on-board fire.

          Comment


            #6
            Thanks for that response WABoating! I figured that the problem started with the devices you indicated, but your explanation really helps. Medallion has also just now responded and their take is that the board is suspect. They would like to do a post-mortem to be sure. In the meantime, my dealer is working to get me the replacement parts. I'll post up the label info from the devices once I receive the new parts. Thanks again.
            Last edited by Tulsah; 07-20-2015, 10:25 PM.
            2013 RZ2 with Convex VX, MLA Custom Sacs

            Comment


              #7
              Update ...

              Tige had agreed to send out a new board, but it didn't arrive in time, so my dealer agreed to overnight a used board they had on hand. The dealer informed me that the only known issue with this used board was that the heater would not turn off. I swapped it out on Friday afternoon, leaving the heater fuse out, and everything powered up without any further issue. I ran through all of the TT switches and outputs, and everything checked out great.

              We were on the lake Saturday morning when I discovered another issue - the Taps up and down were non functional. With some testing, I was able to determine that the hydraulic pump was still functional, which led me to suspect these outputs on the board were also fubar. Surfing with Taps at 1 just doesn't work, so I figured out a workaround for the weekend. Nav light became Taps up and anchor light became Taps down. With some quick on-off touches, we were able to set everything as conditions dictated.

              The dealer now has the new part from Tige, and it will be here by mid week. Hopefully, with it installed, everything can go back to normal operation. What a pain!
              2013 RZ2 with Convex VX, MLA Custom Sacs

              Comment


                #8
                Hmm... I'm starting to wonder if those units are designed a little too close to their margins for long term reliability. "It works in the lab" is a lot like "The engine runs just fine on the trailer". You've got to get your stuff out there in the field under real-world conditions to really know if it's going to work.

                Comment


                  #9
                  can't say I disagree! Funny thing is that in talking with the engineer at Medallion, he told me that this is the first failure of this type that he's aware of in 25,000 units. Tech staff at Tige also claim they've never heard of anything of the like either. Hard to say if it's truth, BS, or somewhere in between... They want the burnt up board back for a post-mortem. I'm going follow up with them after a while to see if they learned of the cause.
                  2013 RZ2 with Convex VX, MLA Custom Sacs

                  Comment


                    #10
                    being a frequent visitor to all the major boat forums, this is the first board ive seen like this.
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                      #11
                      The only reason I openly wondered about that was because first you had your problem, then:

                      used board was that the heater would not turn off
                      ...followed by:

                      Taps up and down were non functional. With some testing, I was able to determine that the hydraulic pump was still functional, which led me to suspect these outputs on the board were also fubar
                      ...which seems like a lot of electrical issues on two copies of the same module in a rather short time. Perhaps a bad batch of components, misstuffed PCB's, who knows.

                      Comment


                        #12
                        The new board arrived today and is now installed. Upon powering it up, I found that the Taps issue remained - everything else worked as it should. So, Out comes the DMM and I start into tracing wires. Once I eliminated the throttle switch as the source of the problem, I followed the rats nest under the helm to where I located yet another 3A fuse - blown of course. With the fuse replaced, the Taps is functioning normally again.

                        The only thing that I question in this is why both the input and output sides of this circuit would be fused?

                        Another question is whether there are full electrical schematics of these boats available that clearly identify all of the various fuse locations?

                        And finally, in case anyone is wondering what an off warranty Medallion Power Module costs...
                        2013 RZ2 with Convex VX, MLA Custom Sacs

                        Comment


                          #13
                          Welcome to the world of semi-custom, relatively low volume electronics. You shouldn't be surprised by that price at all. Bear in mind that Tige doesn't pay that price, but still. Just like the six digit costs of the boats we all love, this is what it costs to make complex products in lower volumes.

                          If only someone had an idea for using off-the-shelf, high volume, and thus far less expensive electronics in boats....

                          Comment


                            #14
                            Hell yeah, that would be a great idea ... wait, I see what you did there ...
                            2013 RZ2 with Convex VX, MLA Custom Sacs

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