Has anyone got the number for the microchip that is on the board in the cluster which then controls the LCD that show's the gear we are in?

Mine got wet and appears to have died.... Just thinking that if its a commercial chip it may be cheaper to replace rather than replace the board.

You could try a search, using the numbers on these ones:

Thanks Inge am going to start a google now!

I have found both of the chips from a UK supplier.... I have had to by 25 of each one mind but it works out at 50p each... so if any one needs to replace there's give me a shout!

try radionics twincarb you might fimd that you can save a heap by buying just 1 or 2 at a time

but when you get it apart there are things to check first

like a bunch of resistors , a capacitor or two and zenner diode that form part of the circuit

question though ....do you need to pull in the clutch to start the bike and or does the neutral light illuminate ?

Hi Charlie,

Just had a look at RS and they are cheaper than the first one's I looked at They still come in packets of 25 mind! The reason for buying the chips is that I have all the other components kicking around either in my electronics parts box here or failing that I have access to them in work!

The bike starts happily in neutral no need to pull the clutch in and the neutral light works. The back light works for the gear number display just it doesn't display the gear. I know that the sender on the gearbox is good (I had to replace it after being hamfisted )

I thought I had taken some photo's the last time I had the clock apart.... one of the chips has got a lot of corrosion on the legs from what I remember which is why I am suspicious that it may be them.... When I next have it apart I will hopefully have all the parts needed so I can work through each component to see if they are working as they should be... May take a while to work through the circuit layout identifying if resistors are in series or parallel.... Unless Inge has a photo of the rear of the board?!

As an after thought should the clock in the instrument panel be back lit? I am presuming that if the gear lcd is then the clock naturally would be (curious because mine isnt)

it kinda sounds like the decoding is working corectly as the neutral function is working ...just either the display driver or the connector that transfers the lcd signal to the actual lcd is corroded

when you get it open it might pay to release the lcb holding bracket verry carefully and see if in fact the rubberised connector strip is corrupted , also note that the pcboard has several small lands that are the connection point for the lcd , which may have corroded up ...i would try a simple clean up first to test that .

unfortunatly the board is behind the tacho clockface ,( but easily removed )

i hope its an easy one to remedy .

strewth min quantity of more than 10 ...im shocked ....i usually see single prices

good luck mate

twincarb wrote: ... May take a while to work through the circuit layout identifying if resistors are in series or parallel.... Unless Inge has a photo of the rear of the board?!

twincarb wrote:As an after thought should the clock in the instrument panel be back lit? I am presuming that if the gear lcd is then the clock naturally would be (curious because mine isnt)

The clock got it's own bulb, between the pins to the cluster connectors.

Just had a sleep.... Was on nights last night am going to go out and wash the K Winter riding here this year is horrendous all we have had is rain and the ground is saturated, so the bike is getting hammered with road grime

I am then going to get the clocks off, I don't plan on going anywhere for the next couple of days so will strip the clocks down on my bench and have a good look

Will replace that clock light while i am at it as well... I thought it was a backlit lcd clock as it was the only thing not lit up when I picked her up from the PO which was a long while back now!

Thanks for the info Gents..... Won't let this thread close till I have some pic on it mind!

twincarb wrote:I thought it was a backlit lcd clock as it was the only thing not lit up

It's a frame around the clock, to keep this area dark on the models which don't have the clock mounted (naked version).

Have washed the bike and stripped the offending parts off as can be seen below. The part that had a layer of rust and which i think is the offending item is the 7 segment driver...

The cost from RS is £3 for 5 so not a lot less than what I had found before.



I checked the bulb for the clock... it's dead so new one to be got!

I have also removed the LCD display and all looks good both with the connector and the pads it sits on.... as you can see the rest of the tracks are looking a bit ropey mind!

hmm doesnt look too bad to me twincarb .

but definatly had some moisture in there , looking at the lower left of the circuit board i can see some furriness around the pads .(but could be just a focus thing )

i would be getting some flux cleaner and a toothbrush to work there . clean up the board with same , suckout the offending chip and replace .

i use a cut and pull method when i dont have a vacume powered solder sucker , which involves cutting the legs of the chip as close to the chip top as possible , what happens is the leg bends as you cut and you can use that bend to hook the fine point soldering iron tip underneath , the leg will then lift straight out as the heat transfer melts the bonding solder . later clean up can be performed on the circuit side with desoldering braid ...which makes a great repair with little possible damage to the tracks and lands .

then reseal the whole pcb (except for the lcd pads ) with clear protective lacquer ....or some paint on humidiseal

If i was in work I would grab one of the Chip desoldering tools! In these days of box out box in a lot of the new guys have never seen one before! I tend to attack things at home similar to your method just get the solder whicker on there first to remove the most of the solder.

I have a can of pcb borad lacquer here so will be giving the board a spray after its had a good clean up. With any luck it should come to life.... Just pondering if I can bench test it....

you should be able to ...but i dont have a pinout to the pc board at hand .

you would need to be carefull not to short out the neutral indicator output though .

a few cheep switches and you should be able to emulate the gearbox switch input to the unit for testing

twincarb wrote:.... Just pondering if I can bench test it....

Should be simple enough............

15 is 12V+
31 is 12V-
Leerl is output to the neutral lamp/startbutton.
A,B,C, is the ones grounded at the gearbox switch.

Have a look at this, for the correct grounding pattern.

thanks inge

my lettering was in black and almost invisible .had to get the maglamp out to identify some

mud map created ....cheers

I have the data sheet for the chips open in front of me..... slowly working my way backwards!

It looks like I should be able to force an "0" o/p on the LED just by making sure I have a logic high on one of the pins which is the enable signal.... If only I was in work could have hooked it up to a scope checked the clock and all the logic levels properly hmmmm lol

Just seen Inge's post

knowing those bits makes it a lot easier... I can just set it up now as if it was in Neutral to give the "0" without having to look for the clock on the counter... would have been handy to be able to do it mind as that would have proved one of it's important jobs!

+1

At the cluster connector.....

Pin 2 is yellow/white.
Pin 3 is yellow/black.
Pin 4 is yellow/blue.

Not been able to get anything to come up on the display... Have confirmed using the link provided by inge that the TGPI switch is working as it should do.... Have traced the connections onto the daughter board itself.

So there is something amis on the board.

Checking the board. the logic i/p for the display chip are showing that it should display an "8" on the display.

The O/P for the display chip are all correct for an "8" the only thing it needs is a sine wave from pin 6.... Oh if only I had an osciliscope here! analogue meter is showing a steady 6v with no fluctuation....

Which means..... Either the Display chip is killing the clock.... The Display is dead.... The Clock isn't being generated by the counter chip....

Oh well was worth having a look to see what the signals were.....

2 choices.... gamble on it being one of the chips cost £13 inc postage.... or £30 to get a second hand board..... hmmmm

that display chip has an option for common cathode or common anode twincarb fogotten which pin it is ...but if the chip was erm cactus it might not get the timing correct or sinking instead of feeding or visa versa

had the tech notes here somwhere but seems to have dissapeared since my last rebuild of my pc

but i do seem to recall that the ripple counter did provide some clock for the lcd refresh ...which i still think it is the display driver not workiing

have a look here http://www.datasheetcatalog.com/datasheets_pdf/C/D/4/5/CD4543BE.shtml

yeah the display chip pin 6 is the one thats used to say what the display your using is... options are:

For liquid crystal displays, apply a square-wave to PH.
For common cathode LED displays, select PH = LOW.
For common anode LED displays, select PH = HIGH.

I am seeing 5v which is good enough for a logic high... Ours is the crystal display cause the others have just 7 segments that can be illuminated where as ours are proper numbers..... Thats if i am thinking straight lol

Thats why i am thinking either one of the 2 chips is dragging the clock down (The clock that maybe/probably to fast for a multimeter!) Or its the display hmmmm... wonder if the display is a standard part....

Twincarb,

I've got another board (I sent one to Charlie a couple of months ago) that works but the liquid crystals 'spread' when they get warm.

If you want it, PM your address and I'll put it in the post, at least you would have something to compare your board with.

Paul.

would love to find one twincarb

i have seen a drawer full of bleeded out lcd displays at the local bmw guy

aye thanks again paul, has been a real help to have it on the bench

Hi Paul,

I may well take you up on that offer, I think i am going to order the chips for RS and fit the display chip first to see if that fix's it... then the counter/divider chip if that fails I will PM you and see if I can prove my display

It's a good job that I enjoy playing with real electronics! I remember when I did it for a living.... now its box out box in

It's almost a surprise it's not a consumable item in itself in the same way that the clock is. Best I have a quick check on the files i have here to make sure it isn't avalible!

Swapped out the 2 chips with new one's today but it didn't change the fault symptom Going to wait for my scope to arrive and then have a scope around on the board.... participially where the lcd screen is attached...

I have found a source for a new LCD in the US price isn't too bad $40 shame the postage is pretty much the same.... hmmmm

You could drop a mail to this repair shop, could be that they got the lcd....cheaper.

Did read in a other forum some time back that they got rather cheap complete GPI units, don't know if it was new ones or rebuilt.

Hi Inge

That was the shop that I emailed yesterday.... found him using a long winded search for "motometer lcd spares"

The postage wouldn't be so bad if buying multiple units from him didn't think that shipping from the US would be that high.

I can source a secondhand circuit board over here I just think it would have been nice to have been able to repair the board I have already.... Shame there isn't a European or Asian source for the displays....

If you don't find a new lcd display / get the old one repaired / find a used one,
you could go for the cheap version.

That is just plain confusing Inge.
Where is neutral?

crazy mad photoshop skillz alert

It is in neutral in my picture......
Ain't got photoshop, only paint......but shure, I could have used a bit more time...

hello everyone

this is my problem.



i need electric circuit scheme
I do not know the value of the diode

sorry for my English

i can try to lift the zenner diode today at work and read the value..... so far zpy ...xx ??

the resistor next to it reads red purple black gold ....so 27 ohms ?

looks like its an "itt zpy 15"
1.3watt zenner ...used for over voltage issues ...
specs says starts conducting at 13.8 till 15.8 volts
i would be guessing any 15 volt 1 watt zener will work ...but replace the resistor to get it all happening again ....

this would happen when the voltage exceeded 14.8 odd volts ......
could be intermittent cable somewhere ? (possibly off altenator to battery ....or earth cable chasis to battery negative .....or some weird battery charger on high boost ....with ignition turned on ?)

Muchas gracias por tu rapida respuesta.

En esta foto que esta en la respuesta # 2 puedo ver los valores que comentas.



Yo pienso en cambiar el zener la resistencia que esta quemada y tambien la marcada como R 15 pues la veo quemada

If you can see the value of the zener diode I change it for the same

thank you very much

Sak3

yes indeed sak ...the resistor is a sacreficial device to let the zener diode do its work

again the values

27ohms 1/2 watt resistor

1 watt x 15 volt zener

in fact the zener might still be ok ,,,,,try replacing the resistor first ......or measure the zener to see if it hasnt become short circuit ....if it isnt ....its done the job as designed . blown the resistor ...and saved the integrated circuits from damage ......well thats how it should work

charlie99 wrote:yes indeed sak ...the resistor is a sacreficial device to let the zener diode do its work

again the values

27ohms 1/2 watt resistor

1 watt x 15 volt zener

in fact the zener might still be ok ,,,,,try replacing the resistor first ......or measure the zener to see if it hasnt become short circuit ....if it isnt ....its done the job as designed . blown the resistor ...and saved the integrated circuits from damage ......well thats how it should work

Good night


Charlie99 thank you very much.


You were right, I just needed to change the resistance.


Again thank you very much

Sak3

Now I would like to get the wiring diagram of this circuit

oops before you go too far ...that zener is cracked ....meaning it has blown up .....please replace as well ....for future protection

ok.

Cambiare tambien el Zener.

En cuanto al esquema electrico del circuito puedes decirme algo.