MDC Repair

[mainekneeboarder]

My gauges have been messing up for a while now, I could make them work by moving the small plug on the MDC unit. They finally quit this past weekend all together but would still try to activate if I moved the plug with alot of effort (they would make the sound but not actually move). I did some research and this seems to be a fairly common issue but no one has really said they fixed it, It seems its common practice to just replace the unit saying its non repairable, or they have tried to take it apart but they just break. I checked prices and availability and wasn't pleased with what I found. I thought for sure mine seemed to be just a bad connection and thought I'd try and pull it apart, it already wasn't working so what harm could I do.

I heated the backing panel with a heat gun to loosen the glue and it came rite off with very little fight. once it was off I could see the problem easily, it was a bad connection at the prongs, the solder had gotten brittle and cracked, there was some corrosion so moisture had gotten in there ( which I suspected because the gauges would work for a while if it was wet/real humid). I just dobbed a little solder on the prongs and cleaned them up a bit, put some dielectric grease on both plug sections and stuck it back together. I haven't tried it yet but am sure this is the problem, I will post tonite for sure. Here are a couple pics.

[mainekneeboarder]

This was really an easy fix, I hope it helps someone out.

[Falko]

Let us know if it fixes the issue.

thanks

[DUKENO1]

Good job kneeboarder! I would have tried the same thing as you...the prices on those things are rediculous.

I have an electronics background and a friend who is an electrical engineer so I was hoping these things

were serviceable. I have a newer boat with the LCD screen in the center and not looking forward to the day

when it all goes belly up!

[GreenMan]

Good job!

[flapjack]

it was a bad connection at the prongs, the solder had gotten brittle and cracked, there was some corrosion so moisture had gotten in there ( which I suspected because the gauges would work for a while if it was wet/real humid).

I expect that connection was hand soldered on that side of the board. That corrosion is from residual flux. Good job on gently getting the cover off and fixing the module!

[mainekneeboarder]

Used the boat for 30-45 mins tonite and gauges worked the whole time.

[Pistol Pete]

This thread is going in the stash.

[mainekneeboarder]

Update, we have put a few hours on the boat now and the gauges are working without a glitch. This fix cured our issue.

[justgary]

It's a shame that manufacturers of marine products don't use some form of hermetic sealant to coat their boards. I guess they think that their case seals well enough, but water has a way of getting into things and not coming back out.

[Pistol Pete]

Yeah,

Like the pitot tubes that go right into the control unit.

Not a good idea.

[kgml]

Where to buy an MDC for my 99 Sporty? The one that I have now is a Medallion 1600, #6607-20004-01E, dated 8-25-1998. Thanks

[SmoothWaterMan]

Don't bash old technology too much guys, it is 14 years old in the OP's case. This MDC was discontinued from new boat production around 2005-2006 if I recall.

Peter

[lukehartwig]

My boat got caught in a pretty bad rain storm last year. First my fuel gauge started acting strange (Reading full then zero). All my gauges went out towards the end of last year. Beginning the troubleshooting process before the 2016 season. 

Anyway, found this great video on the medallion mdc-1600. 

 

Hope it helps!

[Srobinson789]

I got the back cover off!  With the heat gun idea it only took about 5 minutes.  There was more glue on my circuit board than holding the back cover on.  Only had glue on about 50%.  Anyway, I can't post pictures because I am too new I guess.  But was wondering if you did anything to the solders on the top right or just put grease on it like you did where the small plug attaches.  I don't see anything as obvious on mine as it looks on yours but I do think some of the solder tips are not as good as they should be.  I wish I could post pictures but if somebody is willing I could email or text them to you for your opinion.  Any other advise would also be greatly appreciated.   I am not an expert by any stretch of the imagination!  Thanks.

[Srobinson789]

Update:  I bought a soldering iron from Lowe's, brought it home, filled it with butane and said "what the heck".  I soldered all of the points that connect to something via plugs and the pitot tube.  Put it back on my boat and as Gomer would say... shazzam!  It works.  If I can do this anybody can - so I would encourage you to go for it if you are sure it's your computer.  Worst case, you still have to buy one anyway. 

[lukehartwig]

On ‎3‎/‎27‎/‎2016 at 11:51 PM, lukehartwig said:

My boat got caught in a pretty bad rain storm last year. First my fuel gauge started acting strange (Reading full then zero). All my gauges went out towards the end of last year. Beginning the troubleshooting process before the 2016 season. 

UPDATE: After a lot of troubleshooting (and nearly ripping out the entire MDC cable bundle and wire harness!), I finally discovered why my gauges went blank. It actually wasn't the MDC at all. It turned out to be two inline fuses leading up to the MDC. I am assuming the rain caused these to short. Anyway, I inserted a picture of the two fuses for your reference, they are the two white inline fuse casings. The fuse in the purple line is a 0.75A fuse and the fuse within the red/white wire is a 2.0A fuse. After I replaced these fuses and hooked up my MDC, the gauges immediately worked. Not sure if these fuses are stock or if they were installed after-the-fact.

Obviously, I am not saying the MDC mods/fixes within this thread are not effective. But, I took my MDC cover off and everything looked great. No corrosion like some of the other images within this thread. So, for those of you really scratching your heads after your gauges have gone blank, I would suggest checking these fuses, as well as your circuit breakers, before you go ripping your MDC cover off (like I did ). It turned out to be less than a $2 fix for me. I'll admit, the big glaring clue that I ignored was I was not getting the desired voltage as described in the MDC troubleshooting guide when I checked the wire harness (Thus, my insane desire to rip everything out!).

 

 

[SLIM]

I was having the same issues. And did all the trouble shooting as mentioned. Finally got the solder gun out and re-soldered the terminals as mentioned above. All my gauges are up and running again. Thank you Kneeboarder !!

[butter71]

I realize this is an old thread, but wanted to add my experience for future reference of others.  Like the OP, my gauges occasionally stopped working.  To get them working again, I would frequently crawl under the dash to unplug/plug the smaller MDC connector.  Learned by trial and error that the gauges would start working again after doing this.  Following the OP's method, my gauges are working again 100% of the time!  (30+ hours, so far).  After opening up the MDC, I was skeptical this procedure would help, as there were no obvious problems with the soldered pins/prongs, but I re-soldered them anyway.  I'm pleasantly surprised that the gauges have been 100% functional since then.  This turned out to be an incredibly helpful thread for me.  Thank you mainekneeboarder, and others who confirmed with their experience!

[mainekneeboarder]

I haven't been on much lately, and just got a notice this thread was linked to, I decided to read thru the comments. Its GREAT to see it helped a few people, thats what this forum is all about!

And just an update on mine, all gauges are still working years later and many hours since the repair. 

[UWSkier]

1 hour ago, mainekneeboarder said:

I haven't been on much lately, and just got a notice this thread was linked to, I decided to read thru the comments. Its GREAT to see it helped a few people, thats what this forum is all about!

And just an update on mine, all gauges are still working years later and many hours since the repair. 

How did this problem originally manifest?  My dad has the same boat as you and occasionally, all his gauges will freeze completely in place.  And I'm pretty sure the temp gauge never moves at all.  Gauge freezing has been a problem in both MDC units that have been in that boat.

[mainekneeboarder]

Thats what would happen with mine, gauges would just freeze. I dealt with it long enough to notice it was better when real humid or wet first thing in the morning leading me to believe moisture was allowing the electrical connection to be made easier. That along with wiggling the plug and being able to make it work. I cant remember the gauges freezing since.

[jhardwood]

Well this is a great thread for me now.  I have a 1998 Response LX.  I noticed as week or so ago that one of the speedos was dripping at the connection to the MDC.  I decided to procrastinate and wait a few more weeks until I pull it for the season (Like mainekneeboarder, I am in Maine and the season is running out).  Today, after returning to the dock I noticed that the gauges were "frozen" (not from the cold :), but because it looks like I have the same issue that the rest of you have experienced).  I am comfortable with electronics and soldering enough to try mainekneeboarder's repair, but I have a question:  Because I have the drip issue, is that symptomatic of the other MDC issue where eventually the speedo connection fails and the water gets directly into the MDC, such that a soldering repair is moot if the water is going to continue to get it?  

What would you do with this situation to try and resolve both the dripping and the frozen gauges?

[Eagleboy99]

Dump the MEdallion system and go analogue.

[Nitrousbird]

On 9/13/2019 at 8:23 AM, jhardwood said:

 What would you do with this situation to try and resolve both the dripping and the frozen gauges?

Convert the speedo to GPS with Nautic Laugic's system (I did this years ago as a preventative measure).  Then resolder as described in this thread.  Done.

I analogue gauges I've seen posted up don't look as good as OEM.  My suggestion will take less time and be cheaper as well, since you still have to deal with the speedo issue regardless.