Avocet 20 Computer Issue

[JoeG]

I have several Avocet 20 bike computers. One works just fine. Two others are giving me headaches!

What I've been doing:

1. Install 386 battery.
2. Set wheelsize calibration to 225 (mph, 26x2.125 tire).
3. Install in mount on bike. Display reads 0 mph.
4. Spin front wheel. Computer display jumps between 4.0 and 68.0. Whether or not the wheel is spinning, and even if it is off of the bicycle. Both "headache" ones do the exact same thing!

If I put the known good computer on while the wheel is still spinning, it reads something like 4-6 mph which is about right.

Anyone have any idea what is wrong or what I need to do differently?

Computer Instructions - http://www.avocet.com/instrpdfs/20.pdf

 

[regan_ev]

Hopefully my suggestion will help as I acquired all the components separately last year (the A20 itself at great expense!) and was desperate to get it all to work. But... I experienced a similar issue with sporadic and erratic speed readings. So I then took some very fine wet'n'dry sandpaper to the contacts which were slightly corroded on both the holder and the back of the computer and it's worked fine ever since.

Good luck, these old Avocets are super cool and need to be preserved!

 

[JoeG]

Thanks for the response. I'l try some sandpaper.

I did try a pencil eraser on the contacts (old military radio mic hack) and maybe that wasn't aggressive enough.

 

[JoeG]

Re:

Tried the sandpaper. It really brightened up the contacts.

But the computers still do the same thing. :?

 

[regan_ev]

Re: Re:

Tried the sandpaper. It really brightened up the contacts.

But the computers still do the same thing. :?

Ahh shît

 

[Shayne]

Have you tried cleaning up the contacts for the battery?

 

[JoeG]

Have you tried cleaning up the contacts for the battery?

Yes; with a pencil eraser. They're tiny, and the metal is quite thin, so I'm hesitant to do anything hard to them. Good idea, though.

 

[itscervo]

Well there's only one left too try . That is to tremove those 3 screws, that they tell you not to remove :twisted: & check the circuit board for corrosion.