Hi,
I have an Avocet 20 cycling computer. I obtained this computer when I purchased a vintage bike, but I have never seen this individual computer work. I do not know if it was damaged when I got it or not. After searching, I was able to locate the manual here: https://www.avocet.com/instrpdfs/pdffiles.html. I purchased a new battery that matches the old one and the number on the Avocet website (386).

However, I cannot get the display to work with a new battery. A few faint, non-identifiable characters appear when the battery is inserted and then fade out with the LCD turning back to gray.

I opened the back and looked at the board on the inside. It looks very good for its age: no corrosion from battery leakage or other oxidation.

I'm wondering if someone out there has taken apart their Avocet 20 computer and could tell me if there's a way to get these working.

Thanks,
Tim

my Avocet 20 worked with no probelm after being put away unsued in my garage for close to 20 years. Maybe the contacts aren't exerting enough pressure for good contact against the top and sides of the battery (the new replacement battery is not as thick as the original, IIRC. Make sure too that the battery you got is the one Avocet recommends to replacement to the original mercury based battery, which is not available anymore, because some batteries, like the some for hearing aids, seem to have less power to drive things like small flashlights and maybe the Avocet 20. If none of these are the problem, it could be the computer is just broken to start with. Could be just the risk one takes when buying used, old electronic items. I always look for some statement from the seller guaranteeing that the item "tested, still works ...or your money back"
Good luck, Hope you find the problem and fix it.

Chombi

I also got one of these on a 1982 Trek that I bought. It's dead, but I haven't been able to find a new battery locally yet. Once I get a new battery, maybe we can compare notes. I think you can see it in the pic below. It's nice Avocet still has the old pdfs up on their site, huh?

That's the correct battery for a Model 20 (which is the very first Avocet computer, by the way - pretty revolutionary when it first appeared, after it was 'vaporware' for quite some time, as I recall...).

Check the contacts inside the unit. Carefully/gently clean them with an eraser on the end of a pencil. Re-insert battery, see if that does anything. If not (and I presume the new battery is OK - have you tested it?), then it may just be dead.

Edit: you have the battery polarity correct, right? "Plus" side should face up towards you when the unit is opened and you're looking at the installed battery....

Thanks for the responses.

I didn't buy the bike knowing that the computer came with it. If it works, it is a bonus. The PO got the bike at an estate sale and said nothing.

simmonsgc, I got the battery at Radio Shack. They are available online.

The battery is new as of today, and the battery polarity is OK vis-a-vis the old battery and Avocet's pdf. I will go over the contacts with the voltmeter.

I had one of these with the same problem,mine had a broken wire.Check your wires and contacts.

Do the wires connecting the computer to the magnet at the wheel need to be hooked up to complete the circuit? Because the computer is removable from its mount, I thought that mounting the computer is not important. The wires are cut, so I will have to fix them. (I think that mounting the computer is still not important as I write this.)

I've had no success getting my Avocets to work with modern batteries. They power up, but won't program or function.

Maybe its just me... they were great little things.

No, the computer doesn't have to be installed on the mount to light up and be able to be calibrated, and to be able to scroll through the functions. If you can't get it working with a known-good correct-size battery, correct battery polarity, and clean contacts, then I think it's likely a goner.

I don't understand this. Are you using fresh known-good batteries? (and not stale, junk Varta ones from eBay, for example...).

The #20 and the #30 need a #386 battery. The #50 takes two of them. Everything else should use a #357 battery, as far as I know....

Yes, took the old battery in and had store match for replacements. Bought a few. Tried in 3 different Avocets I have. Numbers will light up, but can't program or switch between ****ions. Stays on all the time. All three. Maybe its not the right battery...

I got a battery for mine at Batteries Plus.

i like fixing things also, but you need to consider the value of the bike computer caompared to the value of your time IMHO

Once the display stays on, it's most likely just a matter of doing the correct button push sequence/procedure to get to the programming function. The instructions to do so and the spec for repalcement batteries can be found in the internet, just google "Avocet 20". I remember it took me a couple of times trying to figure it out before I finally got into the programming to input the correct wheel size, then it work correctly after then. The new battery I got lasted only about a year (much less than what the old mercury batteries used to last, IIRC....which reminds me I should get a new battery soon.

Chombi

Not only do I have 3-4 of the original Avocets, I have the original instructions!

For the OP - it's very common for older LCD displays to fade over time with exposure to UV from the sun. Considering that this bike computer was most likely used outdoors, in direct sunlight, for years and years, it's highly probable that the liquid crystal has broken down to the point where it is not able to conduct the electronic impulses that would normally result in discernible characters.

My final verdict on this computer is that it's toast. Thanks for your responses.