Nec Mobilepro 900c battery lock switch broken

Hi all,
So I wanted to learn about the MP900c and what made it tick so I bought a few off ebay and actually got 4 out of the 6 working. So ... I'm getting a little better @ understanding the hardware. The MP900C has a little switch that does not allow the unit to power up. This switch is activated by the battery lock slider. The switch is making the unit think the lock is unlocked and not allowing the MP900c to power up. The switch is actually broke. My question has anyone disabled the switch and how did you do it. Seems a shame to trash an otherwise perfect MB.

Thanks
TM

well you can order a new switch to fix this, quoting from old posts.. unless you meant something else


I looked through my Digikey catalog and found a panasonic ESE22MH. Its the same dimensions but much sturdier looking with a thicker switch tip.
They're 82 cents on Digikey.com just type in the above part number.

The only thing the new part doesn't have is the side terminals. These dont do anything on the original besides hold the top of the case on. The new one is all plastic, no cover to solder down. The little 'tail' that sticks out between the leads helps to keep the front against the board.

..... and the happy end:

Well thats it, if anyone ever needs to replace this switch, the ESE-22MH4 is a perfect (and more sturdy) replacement.

~Mike Steinbach



btw the switch can be broken in a way that the 900/900c will still turn on...i guess that's when it is broken in locked state. then it will never realize if the battery lock is unlocked, otherwise it will warn you it is unlocked

so even if is unlocked..it should power up and tell you to re-lock it, until then it's just unusable but does power on. so maybe i mean a different switch ?

in the case i was talking about, the bootloader is what checks for the state of the switch, easy to patch out but i never got around to testing it because i'd prefer not to risk this... i've been able to load the bootloader into RAM but testing this thing is a bit hard

if i could get jtag working i could test just about any crazy patches to the boot process easily.


Edited by cmonex 2007-11-15 6:04 AM

Thanks ...

Question 1:
Does anybody know when the little trip switch is up if it's open or closed. I'm thinking that the switch is fairly useless and I would like to just defeat it while I'm inside the box. So I guess my question is do I leave it in the open or closed state.

Question 2:

I also like the idea of trying out the boot patch. Is it available? I would be willing to test it out. You will have to tell me how

TM

not available no, until it is tested. BTW if your unit already has the problem that won't help as it won't let you reflash a bootloader.

Hi All,

I got the answer .... The battery switch is open when the battery is in the locked position. Once I figured that out I cut the side terminal(strap like) and opened up the switch. There is a little spring inside which closes or shorts the contacts. I removed the spring and although I don't have the "Battery Not Locked" warning screen, I have a functional unit.

I did order the switch but not sure it's worth taking the ubit apart to install. The MP900's are not made to be opened and closed on a regular basis.

Thanks and I hope this info comes in handy to someone in the future

TM

neat stuff!!

FWIW, I had the broken switch problem on my 900c some time ago, and after about a dozen unsuccessful repair attempts, I finally realized that I could just physically remove it altogether and have it work. So I removed it, and it functioned fine for the day or two until I broke another connector on the mobo.

Geez - it make's you wonder whether NEC put more than 5 minutes of thought into creating the MP 900 series. There are so many design flaws in them that, had they been automobiles they would have been recalled.

It's to bad, because the NEC MP 700 series was superbly crafted...obviously, this is just my opinion which is based on my experience with these H/PCs.

I'm sure others will claim that the 900 series is the best ever, all the power to them!