Autohelm Personal Compass playing up with new batteries

[rhumlady]

I hate button cells with a vengeance!(?) The number of pieces of kit I have both at home and in my work as a computer engineer which work fine till the battery dies then after replacement you get problems and short battery life. I do use nitrile gloves when changing them but still have problems. I now put it down to bad quality control but why they work out of the factory is any ones guess. Having said all this my pal has a 2 year old Mondeo which has a keyless ignition, you have to have a keyfob within range and the car will start when the button is pressed. He got the battery swapped under warranty and it lasted 2 months before reporting low battery again. This got me checking the routine for my Freelander keys which require me to remove the battery and press the buttons for about 10 seconds to discharge any residual current prior to putting the new battery in. This would effectively hard reset the fob. I think that is what has maybe happened to your compass when you left the battery out for an extended period.
Rant over.

 

[lenseman]

Hello Ian

Having read through all the above messages, I can state with authority that your device is suffering from an high resistant joint/connection or component.

They clue is in your message 17 where it states that:

"TRying the light worked but meant the display faded to almost nothing suggesting the batteries are low. Then within about a minute...odd 'illegal' display of nonsense characters followed by power down."

The light circuit is 'high current' (mA) relative to the functioning circuitry of the rest of the unit which probably draws only µAmps. The light circuit will cause micro heating at the faulty junction and caused the unit to become open circuit (OC) and fail. There is no question about this, non at all. This is your fault.

Now the problem is finding the faulty junction. This type of repair requires high ambient lighting and magnifying glasses and a steady methodical approach. It is the only way.

If you are in the Portsmouth or Gosport area and can get down to my yacht, I will take a look for you.

 

[iainhu]

Hello Ian

Having read through all the above messages, I can state with authority that your device is suffering from an high resistant joint/connection or component.

They clue is in your message 17 where it states that:

"TRying the light worked but meant the display faded to almost nothing suggesting the batteries are low. Then within about a minute...odd 'illegal' display of nonsense characters followed by power down."

The light circuit is 'high current' (mA) relative to the functioning circuitry of the rest of the unit which probably draws only µAmps. The light circuit will cause micro heating at the faulty junction and caused the unit to become open circuit (OC) and fail. There is no question about this, non at all. This is your fault.

Now the problem is finding the faulty junction. This type of repair requires high ambient lighting and magnifying glasses and a steady methodical approach. It is the only way.

If you are in the Portsmouth or Gosport area and can get down to my yacht, I will take a look for you.

Thanks for this. Makes sense to me but made me try the backlight; works perfectly!

Your theory seems to build on the 'heat gun solution' as a way of trying to find and resolve the bad joint 'wherever it may lie'. I like your idea of bright light and good magnifying glass though...

 

[Cari bean Pie rat.]

battery change

I had a look at this device.
The "master reset" might be in the pressing of the buttons.
It might be holding down one or more of the buttons whilst pressing red button.
Still sounds like memory corruption to me.
Try holding down buttons in various combinations for 5-10 seconds and it might reset.