(Dumb) Question

When you have good strong cell battery in the NEC MP 900 should it not keep everything while you switch out the main battery while not on AC?

If I pull the main battery not on AC, it hard resets every time.

Am I wrong in my understanding of how this works?

my 900 has a new cell battery. I’ll try it tonight and let you know.

always on it answering my questions. Thanks torch.

Yes, it should maintain the memory while pulling the battery to swap it out.

Mine doesn’t maintain the data either.
I took out the battery + backup battery says “Good” in power properties
My version is
Firmware version P530_42 2.02
Build date Apr 30 2005
Firmware ID 4.15.7
Boot loader 4.10

Edit: I think one thing you and I have in common is we both had hpc2000 MobilePro 900 that we upgraded to 4.2. I don’t know if that’s the issue or if it’s something else. I’m still new to this model as well (I just got my first 900 last month )

Edited by torch 2022-10-14 4:15 AM

There are no dumb questions, only the occasional dumb answer by mods like me. My dumb answer to this question: sounds like there could be a loose or corroded connection.

torch,

Thanks for checking on yours.

Mine is below:

Firmware Version: P530_42 2.02
Build Date: Apr 30 2005
PIC Firmware ID: 4.19.7
Bootloader Version: 4.10

According to Rich it should maintain so I have no idea what is happening. Oh well...

The backup battery is brand new.

Another mystery, I guess. Nothing shows amiss in any of the settings.

Surprised you dont get a low backup battery alert...I double checked both my 900 & 900C...both work the same way...pull main battery with no ac power supply...lose nothing in memory...also double checked users manual...page 2-11, confirms it should provide power to memory without ac or main battery in place...

You might want to tear the unit down and trace the power for continuity...

I'm scared to mess with it, but maybe I can be the guinea pig and see if the cmonex ROM 2.0 or HPC2000 have the same issue?

Also, is my firmware ID a problem? I noticed it's not the latest version, but everything else is correct

I realize you mentioned it's a hardware problem most likely, I just was wondering if it's worth flashing diff ROMs and see the effect

Edited by torch 2022-10-14 8:31 PM

I might try that Rich but I see no other indications that there might be a hardware problem. When I look at WR-Tools ResInfo it shows Backup Battery at 3.251 V (80%). And if I look in Control Panel Power Properties it says Backup Batteris Good. If there were a continuity trace issue would those tools show all good?

You wouldn't think so...but maybe a simple intermittent contact problem when the main battery is pulled...

For information... I tried two different things last night so this might have been me doing it wrong.

1. I closed the lid, removed AC, pulled the main battery and replaced it with a fully charged one. System hard reset.
2. I clicked Windows, Suspend, closed the lid, removed AC, pulled the main battery and replaced it with a fully charged one. System was fine. No hard reset.

So, is this expected, and it was just me being stupid by not suspending first?

Thoughts?

You shouldn't pull the power from any running computer, it won't transition to low power. A CR2032 can't power active memory, let alone flush the CPU registers.