[SPARCbook] Power problems

[Liam]

As it happens, the LCD has been a bit intermittent. At the moment the
machine will not even switch on with the charger lead connected. With the
plug removed, it starts and runs like it should. (I have obviously
complicated things by wiping out the NVRAM settings. I've done a
'set-defaults', but I don't think that's helped too much). When the charger
plug is reconnected, the LCD momentarily shows a + sign after the battery %,
and then shuts down. As a matter of interest, pressing 'pause-r' shuts it
down when there is a hard drive installed.
   Just once, I started the box with no hard drive fitted, and the orange
light came on. (Another thing...neither of the lights work). I connected the
charger plug, and it stayed switched on. The orange light stayed on and the
LCD was blank. Presumably with no disk in, it would use very little power,
anyway; but I left it running for quite a while, and I'm pretty sure it must
have been running from the charger. This has not since been duplicated.
   As I've been trying things as I'm typing this, I have also noticed that
the NVRAM is not getting to run a memory check. If I press 'pause-a'
straight away, I get an ok prompt. If not, it just freezes. I hope I'm not
making things worse by trying, here.
   Thanks for everyone's help. I seem to have dominated this months digest!
I think I've got to accept that this isn't just an intermittent fault that
will go away by pressing the right sequence of buttons. I have been given
some really useful information to take to my local electronics repair shop,
though, and I reckon the bloke there could sort it out. I will let you know
how it goes. In the meantime, any other thoughts or prompts would obviously
be really gratefully received. I can't see me getting to the shop before
next Saturday, so I will keep playing with it in the week.

Cheers, Liam



----- Original Message ----- 
From: "Borgen_Gary" <gary.borgen at verizon.net>
To: "For owners of Tadpole/RDI's SPARCbook series of portable Sun-compatible
computer systems." <sparcbook at sunhelp.org>
Sent: Sunday, April 25, 2004 5:00 AM
Subject: Re: [SPARCbook] Power problems


> I recently had a Series 2 battery re-celled.
>
> The outside two terminals are +12V, the middle one is ground, and the
other
> two go to a circuit card.  The circuit card contains a portion of the
> charging circuit and a temperature sensing circuit.
>
> As a side note:  The pack can easily be re-celled. Just make sure when
they
> split the pack open that they do it on the side and not the middle, since
> the circuit card is in the middle between the batteries.
>
> There are two other things that can go wrong in the power system of the
SB3
> series.
> 1.  There is an IC that is used to measure all the DC-DC converter
outputs.
> 2.  The LCD status display board also contains a small processor that
looks
> at the power supply measurement IC (1) and takes care of power cycling and
> watch reset functions.
>
> Are you getting any indications on the LCD status display when operating
off
> the external DC or battery?
>
> ----- Original Message ----- 
> From: "sunder" <sunder at sunder.net>
> To: "For owners of Tadpole/RDI's SPARCbook series of portable
Sun-compatible
> computer systems." <sparcbook at sunhelp.org>
> Sent: Saturday, April 24, 2004 6:52 PM
> Subject: Re: [SPARCbook] Power problems
>
>
> > Liam wrote:
> > >    Could it need 5v somewhere? There are 5 terminals on the battery,
any
> idea
> > > what they are all for? Could I have my 12v in the wrong place?
> >
> > I remember that the extra leads were for a thermoresistor - to prevent
> > overcharging the NiMH cells.
> > _______________________________________________
> > Sparcbook mailing list  -  Sparcbook at sunhelp.org
> > http://www.sunhelp.org/mailman/listinfo/sparcbook
>
>