Control board repair.

[Mr. Wright]

Was working on Shain's bike today. The previous owner had a start button mounted to the top of the valve cover, so I took the control board out to see if it needed cleaning. Upon inspection, I found none of the buttons worked. I peeled the plastic off and checked under them and they were clean. I started doing continuity checks and found it had a ground problem.
In the picture below, the diagram shows how the grounds connect between the buttons, then stops at the ground for the brake light switch.

The circuit board then continues on the back side of the board to the ground pin.
See pointer in picture.

What I found was the circuit on the back side was burnt completely out of the board.
So I took a small piece of wire and soldered it to the brake switch ground. I didn't want it to touch the button, so I ran it over the edge of the board.

And soldered it to the terminal.

Put it all back together and it worked like a champ.
If any of you have old , bad boards laying around, I would be interested in looking at them, to see if I can fix them too.

 

[Little-Boo]

Good Work and Patience too. I would have tossed the PC Board and popped in a new one. I am not to good with stuff like that, simple electrical circuits and wiring I can handle. PC Boards and EHC bypass is over my head and to old to start learning

Carlos

 

[Hirter6Pack]

Nice job Mr. Wright thanks for the pics and the info. I'm sure Shain will be very happy. Glad to see you getting him fix up.

 

[SKOGDOG]

You just get that little brain of yours into everything, don't you? Good save, Shannon.

 

[FrankBDPS]

Way to go Shannon. Good work.

 

[BWG56]

Nice fix

 

[JeffM]

If any of you have old , bad boards laying around, I would be interested in looking at them, to see if I can fix them too.

Shannon you may regret that offer, i have at least 3, and that is just over 5 year period.
I would hate to think what everyone else has laying around.
Nice job though, Deaddog and i have had several (unsuccessful) attempts to do exactly what your doing, we even had a jeweller solder one as he had the fine solder and iron. This lasted about a week.

 

[Jersey Big Mike]

2 Big Dog, 8 yrs and still haven't had to fix or repair one.
Having done electronics since the early 70's and worked in the computer industy, I can tell you that repair of these boards should be a major issue. When I saw the initial threads on this I was actually getting ready to make new ones for myself as a preventative measure.

Good job -- not everuthing needs to be replaced all the time, even electronics can be salvaged,

 

[TapioK]

Was talking with my friend who is in business. There is a company (in China I suppose) that prints prototype boards. That means 250 boards min. Those cost next to nothing, but the problem is none of my friends knew where in the hell you find those momentary switches.


Tapio

 

[TapioK]

Another thing is when he saw the right hand board with broken brake light connection, he asked why don't I fix it by just soldering the wires from reed straight to the big connector, why route them thru the board at all. Well all I could say was because I am an idiot.


Tapio

 

[Th3InfamousI]

Was talking with my friend who is in business. There is a company (in China I suppose) that prints prototype boards. That means 250 boards min. Those cost next to nothing, but the problem is none of my friends knew where in the hell you find those momentary switches.


Tapio

Axle had some printed up and he was looking to find the domes. Although in 2004 there was no domes just printed boards it's not necessary. The domes just provide a firm click.

Sent from my 831C using Tapatalk

 

[TapioK]

Axle had some printed up and he was looking to find the domes. Although in 2004 there was no domes just printed boards it's not necessary. The domes just provide a firm click.

Sent from my 831C using Tapatalk

An other problem is that silicone "condom", though I suppose you can get those from China too if you send them a model. Minimum order may be 1 million though.


Tapio

 

[BWG56]

An other problem is that silicone "condom", though I suppose you can get those from China too if you send them a model. Minimum order may be 1 million though.
Tapio

I think a couple of heavy duty Trojans would do it.

 

[cdogg556]

I think a couple of heavy duty Trojans would do it.

 

[Matheny 514]

Great job Shannon, excellent information.

 

[BigDogBro1]

stainless steel

Axle had some printed up and he was looking to find the domes. Although in 2004 there was no domes just printed boards it's not necessary. The domes just provide a firm click.

Sent from my 831C using Tapatalk

The control board pictured actually uses the stainless steel domes to make the circuit when pressed. The outer rim portion of the dome sits on PCB pads and when the dome is pressed it makes contact to the center PCB pad under the dome completing the circuit. Domes are available in different diameter sizes, tactile pressure, outer design style and more options. Not sure where they can be had in small quantities but they are not hard to find online. Sometimes you can get lucky and find a dome that matches close enough and use it from another junk device.

The domes can be reused if they are not collapsed and are normally stuck to the underside of the polyester overlay cover with double sided adhesive. They just peel off. If you gently peel off the dome covers stuck to the overlay you can see any corrosion on the PCB and domes if they have been wet many times. Sometimes using a pencil eraser you can gently clean the PCB contacts and the domes which may correct a switch that fails to work when pressed.

The Silicone button overlay is a custom molded part that has rubber pegs on the backside of each button to push on the dome. Years ago I had an OFF button that was not always working well unless you applied more than normal pressure. After examining the dome which looked okay I added (CA glued) a piece of rubber about 1/32" thick to the button peg to extend it a bit more (after testing it first). This corrected the feel of the button and it started working as normal. There's no magic under the cover, just simple engineering.

I have designed membrane type key panel keyboards using this and other technologies.

Doesn't the Bigdog manufacturer still use the original hand controls?

 

[Mr. Wright]

I guess I never followed thru with this thread. I found that the reason the wire burnt on the board was the the battery ground cable was bad, and it grounded back through the board when he tried to start it.

 

[TapioK]

stainless steel
The control board pictured actually uses the stainless steel domes to make the circuit when pressed..... .

Doesn't the Bigdog manufacturer still use the original hand controls?

Yes they use and also sell them, by pairs, $250/pair......