Posts: 280
Threads: 38
Joined: Jan 1970
Instead of the HP battery pack, you can use two 1.5V
Alkaline batteries. It works.
Yours.
Posts: 145
Threads: 40
Joined: Oct 2005
Hi Harry
That calculator doesn´t work without batteries. If you plug the charger be sure you have rechargeable batteries inside or you could damage it.
These calculators always fail because of broken flex connector. I have found just once one spice non working after repairing this connector. I replaced all the capacitors in the AC/DC circuit and it worked. First of all try to replace the flex connector for wires. And test it with alcaline cells. Take care with the poarity. The contact closest to the top of the calculator is "minus". You have to apply 2.4-3V in the contacts (two alcaline AA batteries work fine as Emmanuel said)
Good luck
Jon
Posts: 4,027
Threads: 172
Joined: Aug 2005
Hi, Harry;
I'm adding an image with a partial view of an HP31 with wires replacing the flex circuit. You can see the points I used to solder the three wires that go to the battery/AC connections assy.
I did not take any measures in this board, but Ellis Easley made a complete description of what he found in this post, along with some other interesting reports. And be aware of the fact that continuous memory Spices (HP33C, 34C and 38C) have a power board that's different of the ones found in regular units (HP31E, 32E, 33E, 37E and 38E; there is no HP34E).
If you need further advice, let us know.
Luiz (Brazil)
Edited: 6 July 2003, 1:10 p.m.