Reparing a power supply 82002A

[Maximilian Hohmann]

Hello!

Can't offer much help apart from this: This charger must be very rare. I have a box full of HP chargers but I have never seen one like this. Nor has google's image search.

From your photo it looks as if it can't be opened without damage. There are several other chargers like that from HP which are welded/melted together. To open it, you must break that weld somehow and I doubt it is possible without leaving visible traces. And even if you manage to open it, the only possible repair would be a replacement of the transformer. Other similar chargers (again: I never saw this one before) have a fuse somewhere between the windings which is not accessible or replaceable. This one might be different but I doubt it, otherwise they would have used a fuse accessible from the outside.

What I would do is keep this charger for completeness of your calculator and keep looking for an identical replacement. I know no other place apart from eBay where to look for that, especially if you want NOS parts.

But I have one curious question: How did you manage to connect this thing with your 220V outlet? The plugs are completely different... For my vintage calculators I have a 220V/110V transformer which has the U.S. type plug on the 110V side. They cost almost nothing and save you from trouble like this one. Even if you have set the 220V/110V switch wrongly, nothing will be damaged.

Good luck with your search!
Max

NB: I just did another search for LR 21061 (that's the second type number below 82002A) and there are quite a few search results. Obviously the same charger was used with Casio and Texas Instrument calculators as well, but with a different cable and plug. So there might be a source for spare transformers! But none of the pictures show it in opened state and I still doubt that it can be opened without damage.