Hi Everyone,

'85 K100RS
Managed to get a second hand LCD display module. No marks or "ink bleed", fitted ok all segments working fine but display very faint. Any ideas folks?
thanks
Ian

perhaps the carbon connection strip (rubbery block between lcd and pc board ) is not conducting quite properly

and needs reseating - cleaning along the conductive edges both top and bottom
isopropyl alcohol on a cotton bud  should work  and very light touches to the rubbery stuff

and clean the pcboard connections where the conductive blocks make contact

just a suggestion

Thanks to charlie99 for suggestions.

Unfortunately cleaning plus alternative "rubber" pads did not improve the situation.

Bit the bullet at the weekend and managed yesterday to convert display from LCD to LED.
Well pleased with result.
I would post a picture but don't know how to join savimg.com which I understand is necessary for forum purposes.

Ian

WINGLESS wrote:I would post a picture but don't know how to join savimg.com which I understand is necessary for forum purposes.

To post my first image, I simply clicked on the Host an image icon, which is the left-most icon in the upper right group of icons in the toolbar. After that, I just followed instructions like the drone that I am and successfully downloaded an image from my computer.  It wasn't nearly as interesting as swapping out an LCD for LSD.

Picture attached ( I hope).
Ian

Wingless a very interesting conversion. What was involved in doing the conversion, was it a direct replacement? A lot of inmates would be highly interested.
Regards Martin.

"A lot of inmates would be highly interested."

Yep, a lot!

MartinW wrote:Wingless a very interesting conversion. What was involved in doing the conversion, was it a direct replacement? A lot of inmates would be highly interested.
Regards Martin.

Oh Martin get with the times they're called "clients" now days. Just as silly but not inmates although it is a better description:lol:
And yes Ian very interested.

Rick I thought inmates would be better than Knutcases, or Fruit Loops.
Regards an apologetic and contrite Martin.

some have done this before

there was a post for the wiring change and the type of led display used ..not so long ago ...

cant find it ...yet

try the search engine ?

MartinW wrote:Rick I thought inmates would be better than Knutcases, or Fruit Loops.
Regards an apologetic and contrite Martin.

Well just so long as the fruit loops are orgasmicly groan

So Fruit Loops it will be.
Regards Martin.

Anyway on this forum we are different.

We are all Knuts. Klients just don't sound the same even if it's more politiKally Korrect.

But we have a very open door too........anything K is welcome.

Hi everyone,
Further to the above, please be advised that the procedure was not my own. 2/3 weeks ago I found an article on this forum detailing the LCD - LED conversion ( I think it was through a link cited in another discussion. I printed off the details for future possible interest, but was mainly concerned at the time replacing like-for-like). This did not work out as noted earlier. I tried again to find the article, "BMW K100, 7 segment gear indicator replacement", but like charlie99 was unable to find it so I worked from the copy I had earlier printed.

So: to this unknown contributor ( UC ) my sincere thanks for your groundwork and design.

Two slight changes I made to UC's design:

1. I used the same digital 7 segment display ( Ebay article no 112039276570 ) that UC advised but I found I was happier with the lesser brightness of  1000 ohm resistors as opposed to the 390's he/she used. This was derived through trial and error using a handful of resistors on a single element of the indicator. No attempt was made at calculating values.

2. I used a cut segment of prototype board only as a drilling guide to ensure the indicator is centralised in the rev-counter window then discarded it. Thereafter I epoxied a 10 pin DIP/DIL socket ( cut from a 20 ) on the component side of the counter pc board and soldered all resistors to this, thus enabling the digital display to be plugged/ un-plugged if replacement was required.

I don't know how the quality would be, but if any interested parties are unable to find this article, I could try scanning my printout and posting it on this forum.

Anyone proposing this change - please use resistors rated 0.6W as larger rated ones at physically too big to fit in the space available.
Also: Great care required removing rev-counter needle. Do not pull or you will pull all of the guts out of the mechanism. I made a small plywood packer straddling the spindle on the back of the RC face and a similar tapered one to slide under the needle hub. re-assembly is just a push fit.

Finally cost: Indicator ex Ebay £1.99 + postage, 7 resistors £0.09 each, DIP/DIL £2.40 both ex Maplin Electronics local depot.
Total approx. £2.70 ( $3.60 USD ) excl postage.

Best wishes
Ian

http://k-bike-knowledge.000webhostapp.com/electrical/PDF/K100%20gear%20indicator.pdf


I think this is what you are looking for Charlie.

Hi Avenger,

That is the very article.

Many thanks indeed. Still don't know who to thank though for original.

Ian

A member called Johnser in Cornwall in U.K.

Link to original post.

https://www.k100-forum.com/t12145-gear-selection-indicator-replacement

cheers guys ,,,thanks for adding to the thread

could well be something our slightly adventurous brothers may attempt

Thanks Wingless and Avenger I have saved it for the future. 
Regards Martin.

Does anyone have a LCD display board from an instrument cluster that they can send / sell to me? I have an idea for a drop-in replacement for the LCD and need the board for mechanical dimensions and electrical testing.

Give me a few days I'll see what I can find in the cave. I need to find what was growling behind a heap of wheels and tyres first

WINGLESS wrote:
Bit the bullet at the weekend and managed yesterday to convert display from LCD to LED.
Well pleased with result.

To supplement information in links already provided in this thread, here is a video link embedded in this thread at Motobrick.com that also might be of use to those interested in this conversion.