seedsbelize2

Hi All.
What makes wired computers go bad? The cable is intact. The head unit has a fresh battery. The contacts look clean but I've done nothing to them. I've tried different magnets too. Flashbacks remembering how to mount them to the spokes.
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pdlamb

IME, the top three things are:
1. Battery ran down
2. Contacts corroded or contact springs died
3. Magnet not lined up with sensor

#2 usually happens several years after installation. You can erase the contacts with a pencil eraser, and that might work. I usually try to bathe my contacts in either dielectric grease or Vaseline -- my idea is to get it on there thick so no water can intrude. Of course, water can intrude up the cable on some mounts.

FWIW, I've had better luck with Cateye wired computers than other brands.

1989Pre 

Have you been using this computer recently? What were/are the riding/storage conditions? The transmitter on your fork blade can get moved, and if it does, you know the drill. The sensor on the fork blade is even more vulnerable. Outside of that, what pdlamb said. I use VDO and have had great luck for six years with the A8. In my experience, wired is much more reliable and simpler-to-operate than wireless.

Eusam

It's rare, but I have seen one bike computer with a failed sensor. It was a Cateye with a reed switch sensor. You should be able to test the sensor with a voltmeter or continuity tester. When the magnet is by the sensor there should be a closed circuit between the contacts for the computer, and when it is away it should open. You could probably replace it if you can take apart the sensor housing, but I'm not sure the specifications of the switches they use.

VegasTriker

If is not a low battery causing the computer to stop working, then the next likely cause on a wired computer is poor contact between the holder on the handlebar and the bike computer. If you can trigger the display to show a reading by pressing the button on the face of the computer (usually right button), then the battery is OK. A couple of days ago my wired bike computer wasn't showing a reading and it was because when I reset it after the last ride it moved the computer slightly away from the contacts. Just tweaking the computer in the mount caused it to work normally again. BTW, this computer is a Nashbar budget "dual" computer and Nashbar has been out of business for a couple of years. It's probably a decade or more old but still working.

AndreyT

What is this supposed to mean? What is "bad" about your computer? Doesn't turn on? Displays wrong speed? Wrong distance? Something else is not working? What kind of telepathic crystal ball are we expected to swallow in this forum to figure out what this question is about?

seedsbelize2

They've been in a box for some years. I'm trying to get a few of them going again. By going bad, I mean the head unit has numbers on it but nothing changes with the wheel rotation. Mostly Cateye. A VDO that, I think will be fine with a new battery. Basically, the head units are receiving no signal.

VegasTriker

This is even easier to solve. As soon as you take them out of the box, slip the computer into the base, and then run the magnet past the sensor at the other end of the wire, If the computer turns on and shows anything, you have a working computer. It may just go to the opening menu where you enter wheel size and date but it will light up. If nothing happens, replace the battery in the computer and try again. I've never had a computer not work after sitting around for a couple of years with the exception of having to replace an old battery.

AndreyT

Ugh... What does "has numbers on it" mean? Are the number coherent or broken up? Does the headunit actually "work" in all other respects, like responds to buttons, changes modes, allows you to enter the setup menu, etc.? If the headunit seems to operate normally by itself, then you simply have to check the connectivity with the sensor. Are the contacts in the headunit base clean? Are the wires intact? This is something that can be resolved in 5 minutes.

Tourist in MSN

After bad luck with various devices that use coin type batteries, I now try to clean off the contacts every time I change a battery. I often use some rubbing alcohol when I do that too, seems to cut the corrosion better.

Eusam

I think seedsbelize2 was pretty clear. The unit powers up, but doesn't register anything when a magnet is moved past the sensor. If the buttons weren't working, or the display was incoherent, they would have mentioned that instead of saying that the computer didn't respond to the wheel motion. They said that the cables aren't obviously damaged, the contacts don't look corroded, and the batteries are fresh. It sounds like seedsbelize2 has used a bike computer before, so it probably isn't stuck in setup mode.

If seedsbelize2 has tried all the different suggestions without any luck, some pictures, model numbers, or information about what is displayed on the computer would be helpful. A picture of the sensor with the magnet so we can see how much distance there is between them and how they are lined up would be good too.

seedsbelize2

This was the first thing I did, and getting no response I tried mounting them, with equal results.

seedsbelize2

In theory. All these points are obvious, and still they don't work. I thought there might be a set of tips and tricks I am unaware.of. i guess continued fiddling is in the cards.

seedsbelize2

Thanks for this thoughtful reply. I have been around the block with these things. I will continue to fiddle, beginning with the contacts on the head units and pickup units .

2_i 

In my memory, the computer should react to its contacts being shortened and then disconnected. I.e., just connect and disconnect the contacts with a paper clip and see whether it registers the turn of a wheel.

MNBikeCommuter

I've had two reed switches fail on me. I replaced them with sensors from discarded computers (enforcing "never throw anything away" ) and the computer activity came back to life.