HP battery eliminator connectors - found

On 2/25/07, Gordon JC Pearce <gordon at gjcp.net> wrote: Here's the basic story. I don't have the exact details without checking the manuals and schematics. The power supplies on HP-1000 E/F systems had a battery backup option. When installed an external battery box would be connected. The power supply would charge the batteries when AC was present and could run off the batteries when AC was lost. To make sure the batteries didn't overheat while being charged there was a thermister in the battery box which would shut down the power supply when the thermister got too hot and its R value got too high. If the power supply has the battery backup option installed but the battery box and its thermister is not connected the power supply will not power up all of the way. The eliminator plug simply has the right R value to make the power supply think the battery box is connected and not overheated so the power supply powers up all of the way. I believe the main supply rails all come up ok without the plug and if you didn't know better you would think the CPU should be working, but I think the firmware stays stuck in a halted state waiting for a power good signal, or something like that. If you're new to HP 1000 CPUs and you hit this you'll waste a lot of time trying to figure it out. If the battery backup option is installed in the power supply you cannot easily remove it. A jumper board in the power supply is replaced with a different board (either an inverter board or charger board, I believe), and if you remove the battery backup option boards you won't have a jumper board to put back in place and the supply will not work without it. -Glen