HP-41CV Battery Problems

[bshoring]

I have an HP-41CV that will only work if I hold the battery pack at an angle. It's the original battery holder with 4 n batteries in it. If I close the holder properly, it won't work. The contacts in the calculator all look clean.

Has anyone had any experience with this problem ?

Thanks,
Bob

[rprosperi]

(04-03-2015 09:28 PM)bshoring Wrote:  I have an HP-41CV that will only work if I hold the battery pack at an angle. It's the original battery holder with 4 n batteries in it. If I close the holder properly, it won't work. The contacts in the calculator all look clean.

Has anyone had any experience with this problem ?

Thanks,
Bob

Definitely an issue of dirty or damaged contacts in the 41. Try cleaning the contacts gently with a cleaner such as DeOxit - they even have a formulation just for battery contacts, though that may not be needed, the normal stuff works pretty well.

Has there ever been battery leakage in this 41? If there has been a spill in the past (even long ago) it's possible the contacts have been eroded or bent by prior cleaning.

Be firm but not too hard on the contacts when cleaning, the material is flexible but can be bent or broken.

If too damaged to clean, you can replace the flex connector, but it's tedious.

Good luck, let us know how it turns out.

[bshoring]

Thanks Bob.

I'm going to order some DeOxit.
Regards,
Bob

[aj04062]

I light rubbing with a orange eraser works well too.

I've found that sometimes this is caused by the screws either being loose or the back case has broken at the screw holes (under the rubber foot). The problem is that there is just not quite enough contact pressure on the PCB and putting the battery at an angle will give it that little extra force it needs. (Remember vectors!)

I hope it is just a cleaning as that is simple.

[BarryT]

(04-05-2015 12:16 AM)aj04062 Wrote:  ... I've found that sometimes this is caused by the screws either being loose...

VERY Cool... I'm glad you posted this... the screws on mine weren't at all loose, however, an ever so slight additional amount of torque to snug them a bit more did the trick on mine. Now it's a happy little 41