Hot swapping CMOS batteries
 

The standard instructions for changing out a desktop CMOS battery say you
should turn everything off and unplug the power cord. But I wonder if guys
who do this kind of stuff for a living don't hot swap the batteries with the
power on, or at least leave the power cord plugged in so the always-on 5V
supply provide power to the CMOS. That should prevent losing the contents of
the CMOS memory, including the TOD and the BIOS settings.

On a related question, I also have an old Toshiba Satellite L35 laptop that
I'd like to replace the CMOS battery on. It looks like I would have to take
the entire laptop apart so I can remove the motherboard, turn it over, and
replace the battery. Or, it turns out I can see the battery through the side
of the wireless compartment, and I should be able the cut a window in the
bottom of the case through which I could switch out the battery, then hot-
glue the window back in place. Is there any reason not to do it that way?
It's a lot more likely the laptop would survive the latter procedure.

Hot swapping CMOS batteries
 

On 11/01/2017 05:42, Peabody wrote:
The standard instructions for changing out a desktop CMOS battery say you
should turn everything off and unplug the power cord. But I wonder if guys
who do this kind of stuff for a living don't hot swap the batteries with the
power on, or at least leave the power cord plugged in so the always-on 5V
supply provide power to the CMOS. That should prevent losing the contents of
the CMOS memory, including the TOD and the BIOS settings.

On a related question, I also have an old Toshiba Satellite L35 laptop that
I'd like to replace the CMOS battery on. It looks like I would have to take
the entire laptop apart so I can remove the motherboard, turn it over, and
replace the battery. Or, it turns out I can see the battery through the side
of the wireless compartment, and I should be able the cut a window in the
bottom of the case through which I could switch out the battery, then hot-
glue the window back in place. Is there any reason not to do it that way?
It's a lot more likely the laptop would survive the latter procedure.



Yes, I added a tag to the battery line, so I could easily swap the
battery , while jumpering in an external battery supply with a bit of a
dropper resistor

Hot swapping CMOS batteries
 

On 1/10/2017 9:42 PM, Peabody wrote:
The standard instructions for changing out a desktop CMOS battery say you
should turn everything off and unplug the power cord. But I wonder if guys
who do this kind of stuff for a living don't hot swap the batteries with the
power on, or at least leave the power cord plugged in so the always-on 5V
supply provide power to the CMOS. That should prevent losing the contents of
the CMOS memory, including the TOD and the BIOS settings.

On a related question, I also have an old Toshiba Satellite L35 laptop that
I'd like to replace the CMOS battery on. It looks like I would have to take
the entire laptop apart so I can remove the motherboard, turn it over, and
replace the battery. Or, it turns out I can see the battery through the side
of the wireless compartment, and I should be able the cut a window in the
bottom of the case through which I could switch out the battery, then hot-
glue the window back in place. Is there any reason not to do it that way?
It's a lot more likely the laptop would survive the latter procedure.


Problem with doing anything with the power on is the unexpected.
Suggest you at least put some tape on the battery so you have
something to hold onto while you try to pry it out.

The other issue is the reset. Assuming you have a reason/symptom
to change the battery, it may be that the state of the memory is
compromised. I've had laptops with rechargeable CMOS batteries
that wouldn't run after I manually recharged them.
Removing/waiting/replacing the charged battery fixed it.

Hot swapping CMOS batteries
 

"Peabody" wrote in message
...
The standard instructions for changing out a desktop CMOS battery say you
should turn everything off and unplug the power cord. But I wonder if
guys
who do this kind of stuff for a living don't hot swap the batteries with
the
power on, or at least leave the power cord plugged in so the always-on 5V
supply provide power to the CMOS. That should prevent losing the contents
of
the CMOS memory, including the TOD and the BIOS settings.

There doesn't seem to be any logic to hot swapping a CMOS battery - many
motherboards have a jumper header to discharge the smoothing caps on the RTC
rail - it holds for at least a few minutes with the battery out.

Usually you don't even know it needs replacing till boot up reports a CMOS
checksum error - then I just fit a new battery and load optimum defaults.
There's only a couple of values I need to set manually.

Hot swapping CMOS batteries
 

On 11/01/2017 20:14, Benderthe.evilrobot wrote:

"Peabody" wrote in message
...
The standard instructions for changing out a desktop CMOS battery say you
should turn everything off and unplug the power cord. But I wonder if
guys
who do this kind of stuff for a living don't hot swap the batteries
with the
power on, or at least leave the power cord plugged in so the always-on 5V
supply provide power to the CMOS. That should prevent losing the
contents of
the CMOS memory, including the TOD and the BIOS settings.

There doesn't seem to be any logic to hot swapping a CMOS battery - many
motherboards have a jumper header to discharge the smoothing caps on the
RTC rail - it holds for at least a few minutes with the battery out.

Usually you don't even know it needs replacing till boot up reports a
CMOS checksum error - then I just fit a new battery and load optimum
defaults. There's only a couple of values I need to set manually.

The clue for me , is progressively worsening internal clock timekeeping.
Incidently , hot soldering a tag, remove the power from the soldering
iron before soldering , while still hot

Hot swapping CMOS batteries
 

On 2017/01/11 12:56 PM, N_Cook wrote:
On 11/01/2017 20:14, Benderthe.evilrobot wrote:

"Peabody" wrote in message
...
The standard instructions for changing out a desktop CMOS battery say
you
should turn everything off and unplug the power cord. But I wonder if
guys
who do this kind of stuff for a living don't hot swap the batteries
with the
power on, or at least leave the power cord plugged in so the
always-on 5V
supply provide power to the CMOS. That should prevent losing the
contents of
the CMOS memory, including the TOD and the BIOS settings.

There doesn't seem to be any logic to hot swapping a CMOS battery - many
motherboards have a jumper header to discharge the smoothing caps on the
RTC rail - it holds for at least a few minutes with the battery out.

Usually you don't even know it needs replacing till boot up reports a
CMOS checksum error - then I just fit a new battery and load optimum
defaults. There's only a couple of values I need to set manually.

The clue for me , is progressively worsening internal clock timekeeping.
Incidently , hot soldering a tag, remove the power from the soldering
iron before soldering , while still hot

Propane soldering irons work very well for this sort of thing -
ungrounded...

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

Hot swapping CMOS batteries
 

On Wed, 11 Jan 2017, John Robertson wrote:

On 2017/01/11 12:56 PM, N_Cook wrote:
On 11/01/2017 20:14, Benderthe.evilrobot wrote:

"Peabody" wrote in message
...
The standard instructions for changing out a desktop CMOS battery say
you
should turn everything off and unplug the power cord. But I wonder if
guys
who do this kind of stuff for a living don't hot swap the batteries
with the
power on, or at least leave the power cord plugged in so the
always-on 5V
supply provide power to the CMOS. That should prevent losing the
contents of
the CMOS memory, including the TOD and the BIOS settings.

There doesn't seem to be any logic to hot swapping a CMOS battery - many
motherboards have a jumper header to discharge the smoothing caps on the
RTC rail - it holds for at least a few minutes with the battery out.

Usually you don't even know it needs replacing till boot up reports a
CMOS checksum error - then I just fit a new battery and load optimum
defaults. There's only a couple of values I need to set manually.

The clue for me , is progressively worsening internal clock timekeeping.
Incidently , hot soldering a tag, remove the power from the soldering
iron before soldering , while still hot

Propane soldering irons work very well for this sort of thing -
ungrounded...

Wasn't that one reason for promoting the cordless soldering iron sold in
the seventies? I forget who made it, Radio Shack sold it under their
name also, but there was something about an "iso-tip". Since it didn't
plug in, you could use it where other irons might not be safe.

Michael

Hot swapping CMOS batteries
 

In article ple.org,
says...


Propane soldering irons work very well for this sort of thing -
ungrounded...

Wasn't that one reason for promoting the cordless soldering iron sold in
the seventies? I forget who made it, Radio Shack sold it under their
name also, but there was something about an "iso-tip". Since it didn't
plug in, you could use it where other irons might not be safe.

Michael

Wal made them, maybe still do. They started out making battery powered
shavers. Maybe that was just another product to that line. The main
usage was for places that you did not or could not get a cord to. I had
one and used it because it was quick heating when I only wanted to make
one or two quick connections. Did not have to wait for the wall powered
unit to heat up. Now I have an iron that heats up in just a few
seconds.

Hot swapping CMOS batteries
 

"N_Cook" wrote in message
...
On 11/01/2017 20:14, Benderthe.evilrobot wrote:

"Peabody" wrote in message
...
The standard instructions for changing out a desktop CMOS battery say
you
should turn everything off and unplug the power cord. But I wonder if
guys
who do this kind of stuff for a living don't hot swap the batteries
with the
power on, or at least leave the power cord plugged in so the always-on
5V
supply provide power to the CMOS. That should prevent losing the
contents of
the CMOS memory, including the TOD and the BIOS settings.

There doesn't seem to be any logic to hot swapping a CMOS battery - many
motherboards have a jumper header to discharge the smoothing caps on the
RTC rail - it holds for at least a few minutes with the battery out.

Usually you don't even know it needs replacing till boot up reports a
CMOS checksum error - then I just fit a new battery and load optimum
defaults. There's only a couple of values I need to set manually.

The clue for me , is progressively worsening internal clock timekeeping.
Incidently , hot soldering a tag, remove the power from the soldering iron
before soldering , while still hot

IME: The time and date data usually survives - but it surprises me every
once in a while.

Hot swapping CMOS batteries
 

"John Robertson" wrote in message
...
On 2017/01/11 12:56 PM, N_Cook wrote:
On 11/01/2017 20:14, Benderthe.evilrobot wrote:

"Peabody" wrote in message
...
The standard instructions for changing out a desktop CMOS battery say
you
should turn everything off and unplug the power cord. But I wonder if
guys
who do this kind of stuff for a living don't hot swap the batteries
with the
power on, or at least leave the power cord plugged in so the
always-on 5V
supply provide power to the CMOS. That should prevent losing the
contents of
the CMOS memory, including the TOD and the BIOS settings.

There doesn't seem to be any logic to hot swapping a CMOS battery - many
motherboards have a jumper header to discharge the smoothing caps on the
RTC rail - it holds for at least a few minutes with the battery out.

Usually you don't even know it needs replacing till boot up reports a
CMOS checksum error - then I just fit a new battery and load optimum
defaults. There's only a couple of values I need to set manually.

The clue for me , is progressively worsening internal clock timekeeping.
Incidently , hot soldering a tag, remove the power from the soldering
iron before soldering , while still hot

Propane soldering irons work very well for this sort of thing -
ungrounded...

Even so - I wouldn't bother hot swapping a soldered in CMOS battery.

Hot swapping CMOS batteries
 

Michael Black wrote:


Wasn't that one reason for promoting the cordless soldering iron sold in the seventies? I forget who made it, Radio Shack sold it under their name also, but there was something about an "iso-tip". Since it
didn't plug in, you could use it where other irons might not be safe.


Wahl made, and still makes them.


--
Never **** off an Engineer!

They don't get mad.

They don't get even.

They go for over unity! ;-)

Hot swapping CMOS batteries
 

On Sat, 14 Jan 2017, Michael A. Terrell wrote:

Michael Black wrote:


Wasn't that one reason for promoting the cordless soldering iron sold in
the seventies? I forget who made it, Radio Shack sold it under their name
also, but there was something about an "iso-tip". Since it
didn't plug in, you could use it where other irons might not be safe.


Wahl made, and still makes them.

Thanks. I suddenly couldn't remember who made it.

Michael

Hot swapping CMOS batteries
 

Michael Black wrote:
On Sat, 14 Jan 2017, Michael A. Terrell wrote:

Michael Black wrote:


Wasn't that one reason for promoting the cordless soldering iron sold
in the seventies? I forget who made it, Radio Shack sold it under
their name also, but there was something about an "iso-tip". Since it
didn't plug in, you could use it where other irons might not be safe.


Wahl made, and still makes them.

Thanks. I suddenly couldn't remember who made it.


You're welcome. :)


--
Never **** off an Engineer!

They don't get mad.

They don't get even.

They go for over unity! ;-)