My speedo's full of water...resolved with pictures.

**paddy** · 30th March 2009, 20:54

I've had a niggling problem since I bought my DR. Water seems into the trip computer (TC) and then condensates on the inside of the window making it almost impossible to see. I had tried to seal it a bit better with silicone, but alas to no avail. I was really just ignoring the problem until I went for a blat down Muriwai beach (see the thread Muriwai Ride Tonight). There was quite a lot of salt water sloshed around and I think quite a bit of it got into my TC. The speedo still worked, but the odometer and clock stopped working so well. Funny that. Real annoying when you don't know when you need to fill up. Anyway, I thought I would post the repair process. I don't have a lot of time, so I might do it across a bunch of posts. Think of it as a RR, but more like a project report. I haven't ever attached photos to a forum post before, so we'll see how this goes.

**paddy** · 30th March 2009, 21:01

The first picture is the TC housing. You can see the old silicone that I had to break around the rim (that's a real pain - I wouldn't ever recommend sealing anything with silicone, it shrinks over time and leaks, and if the seal isn't perfect and you need to redo it - it's hard to break, and even harder to clean off). You can also just see the water. It's more obvious in the next few photos. I gave it a real good hosing off when I got home in the home of displacing as much salt as possible as I knew I wouldn't be able to open it and do it properly until the weekend some 5 days later.

**paddy** · 30th March 2009, 21:03

The first time round I hadn't stripped out the buttons as it involved breaking two plastic rivets that then can't be replaced, but it is a likely source of the leak (or one of the leaks) so this time I went ahead and did it. There was quite a lot of water under the seal so it was probably a good call.

**paddy** · 30th March 2009, 21:05

The rubber cable grommet at the rear was also a very likely source of water ingress. It had quite a lot of water around it. You can see the PCB where the cable comes in is quite corroded.

**paddy** · 30th March 2009, 21:13

The is a large plastic cover over the LCD panel. The panel is glass and sits on top of two pinkish foam blocks. The display is backlit with six orange LEDs. It turns out that the pressure that the cover was putting on the LCD was masking a dry joint, but I will get to that later. (What looks like damage on the LCD is just an artefact of the camera lens probably from the sun coming in the window behind me.)

**paddy** · 30th March 2009, 21:19

I had some PCB cleaner that had been hanging around for a long time. I emptied that every where (you can buy this stuff at Jaycar electronics). There wasn't much left and I needed something else. Ideally I would have used isopropyl alcohol, but that is actually getting harder and harder to get - the chemist can supply small and expensive quantities, but even they didn't have any. (I believe BOC gasses will supply larger quantities.) Eventually I settled on acetone (well, actually it was nail polish remover - it had acetone in it amongst other things). That seemed to do the trick although I did try to avoid the LCD panel. I made sure to slosh plenty over the buttons to clear out any water that might have gotten into them.

**paddy** · 30th March 2009, 21:21

This is what happens when you wife figures out why you are taking pictures of what you are doing and declares that "clearly you need to be in the pictures to". The second one is my, great-just-what-I-wanted-I-always-look-like-a-dork-in-pictures face.

**paddy** · 30th March 2009, 21:24

Next we need to think about how to re-seal this thing. Off to the hardware store. Nothing. Fall back to repco. Bingo. Lots of stuff for making gaskets. This sounds promising, so I grab a tube of Gasket Goo. It claims to set solid and yet be separateable. Better still, it's only $10 for the tube (which might sound like a lot for a small tube until you see the sort of prices for this kind of stuff).

**paddy** · 30th March 2009, 21:26

I couldn't resist opening it up to see what it was like. Okay...I really wanted to know what colour it was. It's black. I think there must have been a compressed air bubble in it somewhere because it pored out. And kept poring out. I gave it a squeeze to eject some and reduce the pressure. It still kept coming. Oh well, we'll get to see how long it takes to dry.

**paddy** · 30th March 2009, 21:29

I also removed the cable mounting from the plastic housing. It's just a little metal wheel with a hall effect sensor mounted on a little bracket. Why this is in the wheel rather than having a cable I don't know. I guess that this way they can use the same wheel tooling for both the analogue and digital speedometer models.

**paddy** · 30th March 2009, 21:36

The cables entering the TC were originally sleeved in a black rubbery/PVC-ish pipe (I'm not really a plastics engineer - it was black and it was plastic). It was quite loose around the cable and it struck me as a likely water entry point. I really wanted to re-sleeve the whole thing. The problem is that any heatshrink that will fit over the connector isn't going to be tight on the cable and is going to be just as bad. Eventually, I decided to bite the bullet and de-solder the cable end from the board. All I can say is what a mission.

There are two cables coming in. All of the ends are terminated into crimp on pins. The pins are then mounted in a plastic carrier (at the bottom of the first photo). Then all of the pins are soldered onto the PCB. The board is through plated which means you end up needing a whole lot of heat to remove the pins. The problem is that I can't apply enough heat to all of the at the same time. Eventually I resorted to side cutters and hacked the thing of. Then I could remove the pins one by one. It's not very need, but the desoldered board is in the second photo.

**paddy** · 30th March 2009, 21:43

I noticed that the second (smaller) cable wasn't actually connected to anything on my bike. I traced the tracks on the PCB and they just disappeared into a large IC. Oh well, work smarter not harder. I threw that one in the rubbish. I can't quite figure out why it needs that many cables. Really. All it does it lights up when the bike is on and display stuff. The speedometer reads through a mechanical cable. To my mind it needs three connections:

+ve 12v continuous (power the clock when the bike is off)
+ve 12v switched (turn on the display and backlight when the bike is on)
gnd (shared ground)

Really, this is way over complicated...

I sleeved the cable in some heatshrink and tinned the ends. The cable was quite corroded along its length so it really didn't tin very well (photo 2). Hopefully this will be okay as I really don't have the tools needed to replace the connected if I were to replace the wires (I would end up needed to replace the bike end to match).

I soldered the cable directly into the board and applied some hot-glue around the cable entry point (on the face side of the PCB - it is really hard to solder through hot glue if this ever needs revisiting) to provide some physical security.

**paddy** · 30th March 2009, 21:44

Time for me to hit the sack. The next instalment will be sealing.

**NordieBoy** · 31st March 2009, 08:17

Originally Posted by paddy

This is what happens when you wife figures out why you are taking pictures of what you are doing and declares that "clearly you need to be in the pictures to". The second one is my, great-just-what-I-wanted-I-always-look-like-a-dork-in-pictures face.

Good to see you're using psycology on it