Problems with my Sigma 1106 Cycle Computer

gb155

I have chnaged the transmitter batteries and the computer batteries and have also changed the magnet but im still having problems with what seems to be signal drops, I can be cycling along and the speed will just drop to 0mph, The green light still flashes when the magnet passes but still it says 0mph, 5 mins later it will burst into life again only to go back to 0mph 30 seconds later, its only 6 months old so I have emailed sigma to see what the situation is, as its an intermittant fault I dont fancy taking it back to the shop, Does anyone know what the problem is ? Any ideas what I can do to sort it out ?


As always your help is much appreciated.

Kieran_Burns

Are you using a mobile phone with bluetooth?

They both run at the same frequency and BT will interfere with the signal.

If you want proof:



is my old cycle comp showing an impossible max speed. All you need to do is put the thing next to a laptop running Bluetooth and it goes nuts.

There are also a couple of places on the way through Derby City Centre where the wireless networks (and there are LOADS) interfere with the cycle comp and I get some wild readings.

Horton

have you tried moving the magnet closer to the sensor (or vice versa) so when it passes, it only just clears? I've found in the past that with some computers, they need to be set much closer than the recommended max distance to get proper constant readings.

gb155

Kieran_Burns, No mate, No BT, Nice reading tho, There seems to be no pattern in where the signal drops (assuming its the signal dropping) in places where it went off on Thursday it worked on Friday and vice versa.


Horton, Yes mate there is only just daylight between then and the transmitter flashes every time it passes indicating that its not a magnet issue, maybe ?

I should add that its been fine for 400 miles and has developed this problem only this week, It has been in some HEAVY rain though and the screen sometimes mists up a little, could that be the issue ?

ansbaradigeidfran

Heavy rain and steaming, eh? That could be to blame.

Attacking the problem as an engineer, the problem sounds like it's here

Magnets --> Detector Circuit --> Maths --> Display

The problem's inside the box, and some moisture dripping/sloshing/evaporating could play havoc with the circuitry. If there are some nice screws that are easy to open, take the plastic(?) case off, and leave the innards somewhere warm overnight. (Put it back afterwards.) If that doesn't help, it could be some fatal shorting damage as a result of the moisture, or just a spontaneous failure of any of the little transistors hidden inside. Gadgets aren't built to be repairable these days, sadly.

gb155

ansbaradigeidfran, Thanks, I will give it ago over night tonight mate, otherwise maybe Sigma will replace it.

gb155

Had it on a radator all weekend, All the misting seems to have gone, Will refit it to the bike tonight and update this after I get home tomorrow evening.

gb155

Well its worked 100% this week, So its either condensation or something even more weird

I checked it all tonight after getting home to see I had by accident put 2025's in when it had 2032's in, I would assume putting a lower number in would cause problems but it has stopped the problems ? Does that actually make sense ?

Anyways one or the other worked so many thanks

ansbaradigeidfran

2025/2032: I assume you're referring to the button cell batteries.

They're the same voltage, but different dimensions. The CR2025 are 2.5mm thick, whereas the CR2032 are 3.2mm. (see where they get the numbers from?) The thinner batteries could be loose in a device designed to take CR2032s, but that didn't seem to be a problem for you.

The CR2032s might have been a bit too big, and bent the circuit board and messed something up (whereas a thinner battery wouldn't), but I don't think that it's very likely, if it's meant to have CR2032s in.

gb155

Thanks for the explanation, It maybe related to drying it out this weekend that has sorted the problems and the battery is throwing me off the scent, will keep a close eye and the CR2025 in there for now too.