Saturday, November 12, 2016

Screen scenes day

What do you mean your chart plotter is growing ferns and has bugs in it? Are you serious? You really are? Okay I'll come over and take a look. One of the interesting things about this job is trying to translate what people tell you about a problem into something useful you can use. More often than not it's collection of vague recollections. It's acting up, it doesn't seem right, there was a message on the screen but I don't remember it, my sonar isn't working. 

The end result is my verbal interrogation skills have to kick in. I sit them down in a metaphorical chair, shine a bright spotlight in their face and sweat some additional meager tidbits out of them. "So Bob what do you mean your sonar is broken? What did you do to it? You'll feel better if you get it off your chest, tell me the truth Bob. Did you push the wrong button? You say you did nothing? Do you have any witnesses? No? This isn't looking too good for you Bob. I think you better call your tech. You're going to need representation, and repair money.

I get it. It can be difficult. It's like telling your mechanic you car won't start. He then thinks to himself there are a zillion reasons why this could be happening. It can be even worse. A owner tells the dealer something is wrong. It's already fuzzy enough now, and then the dealer calls me and makes it even fuzzier. Hi Bill, something is broke on Bob's boat, can you go over and fix it? Hell I don't know Bill, it's something to do with the electronics, just go fix it. 

In this case when I was told there were ferns and bugs in his chart plotter I'm not sure I could have done a better job of describing it. I just gawked at it for a moment trying desperately to think of something to say that sounded real smart. Failing miserably at this I just blurted "It's broke and it won't grow back."

So what has really happened? Beats the crap out of me, but this won't stop me from speculating. This is a Raymarine RL 80C MFD circa 2002 with a Thin Film Transistor (TFT) LCD display that needs all kinds of mystical dark arts to manufacture. Although many are still working, most have ended up in a paupers grave. Often this a unmarked dumpster somewhere behind a shopping center. 

If you blow the image up in the lower left hand corner it looks like there was an impact. You can see a star pattern radiating away from it. This may have caused a delamination that was the starting point of the problem. The ferns I think are possibly a chemical reaction that is propagating inside the layers of the display. It has a very fractal feel to it. It's dead like Elvis, can't be fixed, and is slated for replacement. It was really cool and alien looking however.

In the same marina five boats away on the very same day there turns out be another screen problem. The reported problem, like many is also infused with obfuscation. The MFD is acting up. Unlike most jobs, I have a little history to work with here.

The MFD was installed by the boat builder. The console wasn't exactly a precision piece of work. When the MFD was set in the console it rocked a bit. This was fixed by screwing it down plenty hard until it fit flush and looked good.

Shortly after the boat was delivered the display started to delaminate. There was no ambiguity about the problem or its cause. A new MFD was installed by the dealer and this time carefully installed but now has some issues. My first guess is the two MFD's have different software versions and I'm armed with the latest software. When I look though the software is current, but the new display seems to have a touch screen problem. Sometimes it seems to work, and others not so much. I used twisty knobs and the ilk to navigate around. I re-calibrate the touch screen and no joy. I call tech support and the general consensus is the MFD might be funky, send it back and install a new one. Sometimes, but not often bad things can happen to new displays. 

Then I caught a glint from the display out of the corner of my eye. I play with the back lighting and squinting at a steep angle I can see a crack about 5" long, not in the top glass layer but in a lower layer. Thinking about the touch issues I played a bit more. If I touch the screen to the left of the crack, it works fine. Touch to the right and I don't have squat. Regardless of any other issues it may or may not of had it will be replaced.

Back in the days of yore ye olde MFD cases were mostly made of cast aluminum. You couldn't force a corner down flush in a wonky console without traumatic things occurring. Today many MFD's are made with plastics. I don't think this is bad thing. There is less corrosion and coating failures. They are also lighter and thinner. However you have to be more careful during installation. If you're not you can stress the case (and all the stuff in it), or break it by over tightening the fasteners. If you have to spot weld them in place with an adhesive use the right ones like silicone and very sparingly. If you use the wrong ones like 3M 5200 the MFD will come out in pieces. The plastic cases, unlike the cast aluminum ones don't like being pried out out of the console with a Home Depot cats paw.

1 comment:

  1. Kurt Larson was nice enough to email me with a much better description than I was able to dredge up. Many thanks Kurt.

    About the Raymarine RL 80C MFD display with the ferns.

    The ferns are are metal dendrite growth due to migration of the thin-film metal in the display. The crack in the screen allowed enough moisture ingress to provide surface conductivity on the display substrate. The conductivity allowed the metal to "reverse-plate and replate" (migrate) itself from one place to another; the fractal looking pattern being one of natures favorite modes of dispersion, like some ferns...

    Thought you might be curious to know a little more about this in case you have already surmised. (I hadn't)


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