soldering LCD display

[camos]

The difficulty separating the plugs was overcome by using WD40 and all the CMU wire connectors looked good but I sprayed them with electrical cleaner anyway. I now have the LCD display out of the CMU. Could a blown fuse be the cause of no LCD display? The warning light is the only thing that lights up when the ignition is on.

 

Looked at this thread on the CMU removal and soldering on a MK1: http://www.venturerider.org/forum/showthread.php?t=33328

 

Hopefully it is the same as doing it on a MK2. Is it the strips indicated that need to be soldered or the connections (bumps)?

[Rocket]

Hopefully it is the same as doing it on a MK2. Is it the strips indicated that need to be soldered or the connections (bumps)?

 

Look for any cracked solder joints on the CMS. But usually they are the ones for the plug terminals, that you had so much fun unplugging the other half from the CMS.......

[Monty]

Also...look at the computer chips on the circuit board. Make sure one doesn't have a hole burned in the top of it. This happens whenever someone replaces the battery, and tries to hook the sensor wire directly to 12 volts, without using a resistor.

[camos]

Look for any cracked solder joints on the CMS. But usually they are the ones for the plug terminals, that you had so much fun unplugging the other half from the CMS.......

Well that makes sense with the plug being so obstinate the solder joints probably get torqued while removing. If they weren't cracked already they probably are now.

[camos]

I got the CMU panel out and the LCD display and examined the circuit board. Everything looked clean with no indication of corrosion and nothing on the circuit board looked cooked or at all unusual. Hooked all the connections together but no joy, the red warning light is lit and the backlight for the display is lit and the neutral light is lit however still no output from the display.

 

I've never been particularly good at soldering so I'm hesitant to try soldering the display circuit board without having a good reason to do it. While in storage the display worked properly over the course of about a year. A couple of months after I had last looked at it, the display was not working. Something happened while it was just sitting there. Could there be a fuse or possibly a bad ground connection somewhere that would disable all the readouts without cutting all the power to the CMU?

 

I'm under the gun if I want to get this thing working so I can attend Cody.

[dingy]

Resoldering is not as bad as it sounds. On the CMU, all that is needed is to heat the solder pad till it melts and add just a bit of new solder.

 

The TCI unit, for example, is a totally different resolder experience. The solder has to be removed in order to free up components for removal.

 

Get a low wattage soldering iron at radio shack, or maybe auto parts store. Something around 20-35 watts is plenty. Also get some thin rosin core solder. Do not use acid core solder as it will eat up components. Also a soldering gun is not an ideal tool for this as they usually have too big a tip and are higher wattage. A gun has a trigger to heat it up when needed, an iron is heated whenever it is plugged in.

 

Let soldering iron heat up, you can tell when it is ready by touching a piece of the new solder to tip and it melts. It helps to secure board somehow so both hands are free. Touch tip of iron to solder connection. Within about 3-5 seconds the solder will melt and change to a shiner color. If there is enough solder on connection, it is not necessary to add more. Try to touch the tip to the wire or lead being soldered so it heats up enough to have solder fuse to it. Do not add so much solder that it could bridge out to an adjacent component.

 

Have a small wet sponge or a folded up paper towel that has been thoroughly soaked with water. Every 2 or three solder joints, wipe the tip of the iron on sponge to clean it off. Just quickly drag it across sponge on both sides. This removes build up from tip and lets it conduct heat better.

 

There is an attached picture of a Class board I think, with some bad joints on it. If any joints are very dull in color or have ridges around them or cracking they are suspect.

 

Gary

[camos]

When I had the circuit board out, to my untrained eye the solder traces and joints looked smooth with no cracks. What about checking continuity to see if there is a cold joint that doesn't look bad? Is it difficult to figure out which trace connects to the plug terminal? Or is that not a good idea?

 

Gary are you suggesting running the iron along the traces to resolder them or just redoing the wires that poke through?

 

Under the circumstances with the bike just sitting on it's center stand for a year or so I'm kinda doubtful that a solder joint is a likely cause. To me the most vulnerable and therefore most likely cause would be oxidation or corrosion at a ground connection somewhere. I still haven't found where the neg term of the battery is connected to the frame or engine. Do I need to remove the fairing to find all the ground connections?

[Rocket]

Gary are you suggesting just redoing the wires that poke through?

 

I still haven't found where the neg term of the battery is connected to the frame or engine. Do I need to remove the fairing to find all the ground connections?

 

Just the wires poking through.

 

Look just in front of the waterpump, by the pipe connecting waterpump to the thermostat housing, is the engine ground. Other ground wires should be connected to the coil mounting bracket, under the left side fairing.