New tachometer doesn't work.

[Horsem4n]

I got one of those cheap tachs with the S1 and S2 buttons and internal battery.
I should have turned it on to test before mounting it to my bike, but it doesn't turn on.
I did accidentally put it in my magnetic parts cup on my work bench and it turned part of the display purple, which I would expect. But would accidental contact with a large magnet break the tachometer?
I'm thinking of replacing the battery to see, but I would have to go out to get a new battery. Just lazy tonight unless someone around me wants to go to Walmart.

 

[zippinaround]

you can remove the battery? a high powered magnet may have cause some damage to it couldnt be sure tho where did you get it?

 

[Horsem4n]

I dont know if you're supposed to be able to replace the battery, but I'm going to see if I can after prying off the back cover.
I got it off of bikeberry.
From what I understand, they aren't the most honest people, but they have been relitively helpful when I needed anything. I bought my kit and everything from them except a couple maniac mechanic parts.

 

[zippinaround]

I would just try telling them its faulty first they might just send another one.

 

[Horsem4n]

So, I tried turning it on one more time before taking it apart, and it turned on after holding both buttons down. I think I tried that before, but I can't remember. Maybe the magnetic interference wore off, or maybe I'm just dumb.
I can't however change any modes or turn it off according to the instructions. It seems to be in the right mode though, so it's no big deal. When the engine is on, it shows rpm, when off it shows the operating hours.
Maybe it turns off by itself? But whatever, it works now.
Thanks for the help.

 

[KCvale]

It never turns off.

 

[Horsem4n]

Ok, I see how it would work this way when they are cheap like this. I imagine if I take the battery out it will forget the operating hours.
How long do these typically work for?

 

[zippinaround]

Says 2yrs in the manual but I'd say more like 1 and a bit

 

[KCvale]

Good luck getting the battery out and replacing it.
Figure a bit more than a year before replacing it.
As for resetting the hour count, seems to me there is a sequence to do that but I don't have a manual in front of me.

 

[Fabian]

You can use a bicycle speedo to create a tachometer. Just install the magnet on the right hand side jackshaft sprocket, and program the speedo for a wheel size of 1172mm diameter.