Digital Speedo Sensor Repair 86 Aspy

[geraldm]

Spent half the summer with out a speedo because the sensor failed . removed it looked for a used one and be dammed if I will give someone 200 bucks for a used one , so i removed the screws holding the 2 halves together gently picked the isolation membrane away and found the problem . the ss451a omni polar hall effect sensor had shorted out (( me thinks from moisture getting into the device caused a short and left signs of heat buildup on the board where the ss451a solders into , the printed board looks ok so i ordered 10 of these sensors . should be here in about a week . i am confident that I can remove the old and solder in new with success . its not just the speedo but the auto volume , signal cancel ( which doesn't stay on long enough when making a turn off on the highway anyway ,,, I really dont like this option and may unhook at the front forks . )), odometer , it seems to me there is something else that doesn't work when the sensor is down cant remember what . anyway i will let everyone know to what degree of success or failure I have with this . It seems to be a fairly simple device for an printed board . hope it works . If anyone has played with these darn things feel free to post your experiences . we need to find ways to keep these old bikes on the road and functioning properly .. have a good one

[CrystalPistol]

Someplace I have seen a thread with pictures of this same repair ..... maybe Steve Saunders site?

[geraldm]

Yea well like a drunken doctor Me going in blind . never figured someone else would be foolish enough to do something like this

[skier]

I think the newer Honda Valkeries use the same sensor. Maybe check the used prices on Ebay. Just a thought.

[geraldm]

yes i heard that a while back but to me its important to try this if it works it will cost about 3 bucks to fix it .

[Rusty Bike]

Yes there is an extensive thread about this on the web. I have read it.

[geraldm]

got the pt# on the web and just chased it to a company that shipped the same day and charged 6.00 for ship instead of 28.00 ... 15.10 cdn. for 10 of them delivered to my mail box ... http://ca.mouser.com/new-customersand is suppose to take 7-9 days delivery . see what happens I guess . me thinks I should get a new soldering kit for this job with a solder sucker and so on ..

[virgilmobile]

you might want to read through this posting about repairing the speed sensor.
Pay particular to the type of sensor used...viewtopic.php?f=12&t=28993

[geraldm]

you might want to read through this posting about repairing the speed sensor.
Pay particular to the type of sensor used...viewtopic.php?f=12&t=28993

Yes thanks i have checked the sensors and the omnipolar ones are whats needed . It was the resistors that I had a bit of a time finding according to the color code the 1/4 watt 6.8k should be the ones , at least that is what was on the link . thanks for your time .. now wait for pieces .

[geraldm]

My resistors were shipped from Vancouver today so they should be here by the end of next week . then its play time fun time . I love fixing stuff I hope the repair works , as you can see there darn near free . http://www.ebay.ca/itm/201705371853?_tr ... EBIDX%3AIT

[Rednaxs60]

Any pictures available? Bookmarked this thread for future reference.

Cheers

[geraldm]

yup , no worries boss . i have a few nice clear pics of the problem area on the circuit board . I will have some good pics of the parts . and when it comes time for the transplant I will get my video camera charged up and upload to my you tube site then set up a link here . I also have a schematic of the said omni-polar ss451a sensor with all the specs but maybe need a little better meter to check the thing out . What I'm wondering is if the said sensor would over heat and burn out from excess speed for long periods of time that little dude does pick or send out I guess up 8 signals per revolution so that thing is really clocking at 100 plus MPH., not saying anything but if that is possible then that could be a reason it quit working . or water getting in and shorting things out ( there was a lot of very tiny water vapor droplets on the inside of the cover when I took it apart ( Last fall and this summer have been very wet here so rode in lots of water ) . and the vibration stuff inside doesn't really look water proof as it has lots of big air bubbles in it , if you have had one apart you probably know what I mean . Yea I will try to make things clear and simple but that not easy when I only know fraction of what I should know to understand the whole unit and how things work . Me thinks i should get a nice interchangeable soldering stick for the job , it would suck to over heat the area with my big guys .. have a good one Rednaxs60

[geraldm]

Bit of an update , and no I won't show how to remove from bike and disassemble . no offence but if anyone needs help with that end then they probably should get someone else to do the job . the first pic shows the new 1/4 watt 6.8k resistors (( me thinks that a larger wattage resistor could be used so long as the 6.8k is the same ))with a dime to give you an idea of the size . the resistors all test 6.81k either way so it seems there is no +or - on these little dudes . these came from trains*plains out of Vancouver B.C. but I'm sure they are available thousands of places it was under 5.00 Cdn. for the 5 resistors including shipping .

#2 pic just shows where I removed the omni-polar switch from the pcb. also beside the three holes is a spot where I removed the wire that grounds the sensor cover to the pcb it was just in the way , I will re-solder it in back place when going back together .

#3 pic shows the opposite side of the pcb where the three omni-polar leads go through and solder as shown in #2 pic ,.. Note the hot spot on the center hole of the pcb IMO that little omni-polar switch must have gotten pretty warm to cause that much heat , That is why I wonder if it is possible to overload this little unit by excessive speed or if it was just the moisture inside shorting it out ?? that hot spot by the way was there before I removed the omni switch so no I did not use excessive heat to melt solder . One thing that I might mention is on another occasion I was well into the 100 MPH range for a good spell and so much power was created by the charging system that the top of the battery blew right off the battery , the only thing holding it down was the battery hold down cover . so maybe it is also possible that the Omni switch was fed so much power over the 5 volts that it could not deal with it and burned up . any thoughts on this would be welcome .

the 4 pic shows the omnipolar switch with 2 of the 3 leads broken off (( too much playing with it trying to do some tests , the center lead of the 3 was a copper color and the other 2 were a ordinary silver color the copper color tells me it was for sure overheated . Still waiting for the omni switches I ordered 10 of them just because they were also very cheap . Me thinks the whole thing could be made including the pcb which would need to be made from an ordinary plain copper solid copper board which I will try later if things go well maybe even if they dont .

[geraldm]

The ss451A Omnipolar digital hall effect sensors came today , bought 10 of them , tiny little dudes , about 1/4 the size of the original

I guess I'll figure out how to mount securely and pick away at it and see what happens . me thinks the main thing here is to get things mounted the same distance from the magnetic wheel .

[geraldm]

Got all my parts together and gave it a go .
#1 pic was just a trial run to see how the hot glue worked to hold things in place , and it seemed to do just fine , that will be a time will tell story but see no reason that it shouldn't work , after the trial run I redone the hall effect switch into its proper position , for that I suggest you take some pics before disassembly to get the idea how far from the magnetic wheel the omnipolar switch needs to be after the switch was placed where I felt it should be according to pic from a previous mod by a different member .

# 2 pic shows the little brass cover back in place covering the hall effect switch , I just added a little more glue and quickly pushed the brass tabs into place through the PCB and held in place till the glue was dry , if everything is done in a careful and timely manner this step should work fine , if not start over , with a different switch , (( that is why I bought 10 of the little guys so I could redo without waiting )),

#3 pic shows the proper orientation of the hall effect switch , for some reason the switch needs to be mounted as shown , unlike the original switch that was attached flat , I'm thinking the magnetic switches are mounted inside the switch in such a way that this is the most effective position , If you notice the small dot on the hall effect switch is pointing out toward the magnetic wheel , for the air gap I just gently but firmly moved the switch around with only a dab of glue on it , after getting it positioned in place where I was comfortable with it , i just layed more glue to hold exactly where I wanted it . you can see the top edge of the brass cover that was put in place after I had the switch where it is . .

#4 just shows where the soldering is being redone . you can see that 1 of the 3 hall effect switch pins have been soldered back into place ,

#5 also shows where I re soldered ground wire from cover back to the PCB. I removed it just because it is a real PITA trying to work around it ,, all soldering is complete in this pic also and the PCB has been washed of all grime from soldering , now is a good time to check and make sure the solder is not bridged the PCB in any way , .

#6is just a top view of the brass cover in place and a good view of the 1/4 watt 6.8k resistor soldered to the 2 outside pins of the hall effect switch , things do get a little tight but if time is taken and a little care everything can be mounted comfortably without touching , I would suggest a trial set up without and solder or glue just to get it in your head where everything goes and in what order will be the most convenient and not in the way of the next step ... In conclusion I feel that all in all the mod is not that difficult and most guys that are handy and have a good feel for soldering should be able to accomplish this task , that said I still have not tested my fix as it's cold outside and goldie is in the porch , . I still have not came to a conclusion of what happens to these switches to burn out like they do , I have almost convinced myself that the burn out is caused by over voltage from the system somehow (( this system without cruise control as far as I can tell is suppose to get 5vdc )) and not from moisture as previously suspected . there must be a electrical wizard hanging around somewhere close here , to possibly put a little light on the problem . anyway I will get some heat in the porch in the next couple days and see what happens ,, and will let you know how it works , If it works

[geraldm]

Update .. Well after much searching for parts , trying to figure how the sensor really works , and what happens to the sensor to make it fail in the first place ,, I am very Happy to say that the mod was well worth all the time I spent on it , it functions very smooth on the speedometer , and also not sure if the OEM sensor worked in reverse , but these little guys also perform in reverse , the reason being that the ss451a Omnipolar Hall Effect switches have no + or - so they perform equally well when the magnetic wheel passes the pickups in the switch regardless which way the wheel turns
also with no + or - they have the ability to trigger more than once a revolution , giving it the ability to make the necessary pulses per revolution of the magnetic wheel ,

So Rednaxnaxs60 the mod is fine and if some of the pics arent quite clear or my ramblings not understood feel free to say . i will try to clarify things ,, N

Now I have ordered 10 new CB's and I am going to make a totally new PCB with all the components .
Again I mention although it is very possible I am wrong but i DO NOT believe this failure is caused by moisture or at least by moisture alone , Me thinks its from over powering the sensor from the computer or where ever the 5 VDC comes from to make it work and possibly both , during reassembly extra precautions should be taken to make sure the sensor unit is water proofed extra well . If anyone wants their old sensor looked at and possibly repaired and dont feel they can do it for themselves possibly I can help you just send me a PM.

[Rednaxs60]

Gerald - thanks for the pictures and info on how you did your fix. I do not have an issue yet; however, being realistic, this may very well happen. I will be ordering up the parts that you have put in your posts, can't hurt to have these on hand especially at the price you mention.

Glad your fix worked. The interesting aspect of these older bikes is that you are turned into a more than jack-of-all-trades. Even if you had not done a specific type of work such as PCB repair, you pretty much have to get to be a pseudo-expert on it.

Appreciate your post on this issue.

Cheers

[geraldm]

No sweat it was fun I hope it helps people get through the problem .. winters are long and cold in pumphandle always need something to do . just trying to get the title changed to better explain what its about , thanks for following didnt think very many would care .

[geraldm]

If anyone has a old digital speedo sensor they dont want , I would like to by it for what ever , it doesnt need to work just be intact , Want to make a totally new PCB for the module but cant remember what all the other components were also the exact size of the PCB so it will fit nicely into the plastic holder inside , I would just send the cash and if ya screw me over I will just get my ex to cast a terrible spell on you .
PM me if anyone has one please . thanks I hope everyone has a healthy 2017 and another safe year of riding .. Geraldm

[julimike54]

Cool info ..................

[geraldm]

Just an update and maybe a caution with people with the digital pickup at the wheel ,
First off my speedo is still working fine and am just tickled . don't remember how many km it had when I repaired it but have probably run easily 18,000 km. .. I noticed a rapidly growing fluctuation here about 500 km. ago. after a full days ride in the rain and then total failure . so just figured my fix was a fail , removed the sensor from the front wheel removed the 4 screws and out came a bunch of water and also noticed corrosion starting everywhere the printed circuit board was exposed , so dried it out the best I could . then immersed the whole thing circuit board all in iso alcohol washed it off gently with a soft bristle brush , did this three times the let it hang and air dry . the next day stuck it back together just for a try and it worked perfect again ( it even seems to be the 3 or 4 km off that they are known for ) so took it back apart and applied a nice bit of silicone high temp to both sides of rubber gasket and around where the wiring goes through the rubber gasket and closed it back up tight , and although I have not been in any rain since it is working perfectly . I guess what I am saying is thinking back to the first time it quit upon opening the pickup , it was corroded and a huge film build up on the whole circuit board , so in conclusion I feel that the culprit is a faulty gasket between the two halves of the sensor ,

Anyone having issues with there digital speedo fading out and then back on you will probably discover the first signs of the digital sensor failing , simply because the small signal created is just lost in the moisture until overload takes place and things short out and burn up the hall effect sensor . i would suggest anyone that gives a **** and is having problems with speedo readouts and is handy should consider checking this out and cleaning inside , ( very carefully and gently ) and seal it up , there should also be no lube on the inside just a dab where the sensor meets up with the drive , Just saying , hope maybe this will prevent a few of these hard to get parts from burning up , have a good one , ride safe , geraldm ,