I have two Dell Inspiron 3800 notebooks and am having the same problem
on both of them. When I press the "on" button, the LED's for the
on/off, caps lock and scroll lock all light up for about 4 seconds,
then goes off. The machines never even show the BIOS info screen.
These machines have been sitting around for a while unplugged, so I
suspect that there is a dead CMOS battery.

My questions are:

1) Does my guess of the CMOS battery being dead sound correct?
2) Is this something someone handy with a soldering iron could do
themselves?
3) Where can I get a CMOS battery for this model?

Thanks!

<vamichael******.com> wrote in message
news:1161703285.391605.160330@k70g2000cwa.googlegr oups.com
> I have two Dell Inspiron 3800 notebooks and am having the same problem
> on both of them. When I press the "on" button, the LED's for the
> on/off, caps lock and scroll lock all light up for about 4 seconds,
> then goes off. The machines never even show the BIOS info screen.
> These machines have been sitting around for a while unplugged, so I
> suspect that there is a dead CMOS battery.
>
> My questions are:
>
> 1) Does my guess of the CMOS battery being dead sound correct?
> 2) Is this something someone handy with a soldering iron could do
> themselves?
> 3) Where can I get a CMOS battery for this model?

Yes it sounds like the CMOS battery is dead to me. And yes you should be
able to replace it. There are lots of battery websites that you should
find a replacement.

--
Bill

vamichael******.com wrote:
> I have two Dell Inspiron 3800 notebooks and am having the same problem
> on both of them. When I press the "on" button, the LED's for the
> on/off, caps lock and scroll lock all light up for about 4 seconds,
> then goes off. The machines never even show the BIOS info screen.
> These machines have been sitting around for a while unplugged, so I
> suspect that there is a dead CMOS battery.
>
> My questions are:
>
> 1) Does my guess of the CMOS battery being dead sound correct?
> 2) Is this something someone handy with a soldering iron could do
> themselves?
> 3) Where can I get a CMOS battery for this model?
>
> Thanks!

1. That's not the classic CMOS failure I'm familiar with, but IF the
systems were highly customized, then I guess it certainly could be a CMOS
battery problem. Pretty unusual for two to go bad at the same time though.
2. The CMOS batteries are not charged, ever, by anything in the computer/s.
It's the same as the ones in your watch; they work for awhile, then they
quit.
3. CMOS batteries are changeable without a soldering iron and usually there
is a small compartment you access with a screwdriver in order to change the
batteries.
4. To get a battery, pull out the old one and take the numbers with you to
the store. Or check the documentation that came with the computers for the
numbers. And how to access them.

It sounds more like the computer's batteries are dead: Are you plugging
them into ac to check them out? The computer's batteries very likely need
to be rechaged.

Pop

The CMOS battery is a possible culprit, but nothing more. Almost all
laptops will work with a completely dead CMOS battery. But some models
won't. Don't know about your model.

Leave the laptops plugged in for 24 hours. Most laptops have
rechargeable CMOS batteries. On some models, the battery only charges
while the laptop is turned on (not simply plugged in, but actually
turned on). Of course, this would be a bad design in a machine that
won't turn on with a dead CMOS battery.


vamichael******.com wrote:

> I have two Dell Inspiron 3800 notebooks and am having the same problem
> on both of them. When I press the "on" button, the LED's for the
> on/off, caps lock and scroll lock all light up for about 4 seconds,
> then goes off. The machines never even show the BIOS info screen.
> These machines have been sitting around for a while unplugged, so I
> suspect that there is a dead CMOS battery.
>
> My questions are:
>
> 1) Does my guess of the CMOS battery being dead sound correct?
> 2) Is this something someone handy with a soldering iron could do
> themselves?
> 3) Where can I get a CMOS battery for this model?
>
> Thanks!
>

Re: "The CMOS batteries are not charged, ever, by anything in the
computer/s. It's the same as the ones in your watch; they work for
awhile, then they quit."

That is categorically wrong. Some laptops do use one-time CMOS
batteries (as you describe above), but many (most, in my experience, but
my experience is mostly with Toshiba and some Dell) use rechargeable
CMOS batteries that are not considered to be user replaceable (although
they are not really that hard to replace). All Toshiba models that I
have worked on use rechargeable CMOS batteries.

"Pop`" <nodoby@devnull.spamcop.net> wrote in message
news:uOq%g.4490$rx.2784@trnddc04
>
> 1. That's not the classic CMOS failure I'm familiar with, but IF the
> systems were highly customized, then I guess it certainly could be a
> CMOS battery problem. Pretty unusual for two to go bad at the same
> time though. 2. The CMOS batteries are not charged, ever, by anything
> in the
> computer/s. It's the same as the ones in your watch; they work for
> awhile, then they quit...

Most laptops use rechargeable Ni-Cad or Ni-MH batteries. Those that use
Lithium button cells are popular in desktops, but rare in laptops. And
how they charge is different. Like my Toshiba 2595XDVD laptops tickle
charge the CMOS battery, only when the backlight is on. If you have the
laptop on 24/7, but has the backlight always off, you will run down the
CMOS battery in about 5 to 6 months. The same thing whould happen if you
didn't plug it in all of that time.

--
Bill

"Barry Watzman" <WatzmanNOSPAM@neo.rr.com> wrote in message
news:453E429E.3010802@neo.rr.com
> Leave the laptops plugged in for 24 hours. Most laptops have
> rechargeable CMOS batteries. On some models, the battery only charges
> while the laptop is turned on (not simply plugged in, but actually
> turned on). Of course, this would be a bad design in a machine that
> won't turn on with a dead CMOS battery.

My Toshiba 2595XDVD laptops only charge the CMOS battery whenever the
backlight is on, according to the manual. This model also sports a
backup RAM battery (yes a third battery). In both of mine, they are
dead. But what they do is to allow you to swap the main batteries in
standby mode (up to 30 minutes of RAM power). Which is a very good idea.
<grin>

--
Bill

vamichael******.com wrote:
> I have two Dell Inspiron 3800 notebooks and am having the same problem
> on both of them. When I press the "on" button, the LED's for the
> on/off, caps lock and scroll lock all light up for about 4 seconds,
> then goes off. The machines never even show the BIOS info screen.
> These machines have been sitting around for a while unplugged, so I
> suspect that there is a dead CMOS battery.

I assume you tried turning it on without the main battery in.

> My questions are:
>
> 1) Does my guess of the CMOS battery being dead sound correct?

Unlikely. Remember, when the system is plugged in, or operating from the
regular battery, the RTC and CMOS are not being powered by the small
Lithium coin cell battery. Many systems use rechargeable "bridge"
batteries, and dispense with the non-rechargeable lithium coin cell. The
bridge batteries allow you to swap main batteries without turning the
system off.

> 2) Is this something someone handy with a soldering iron could do
> themselves?

It depends where the battery is located. I couldn't find any information
on this. On some notebooks, it's accessible via a panel on the bottom,
maybe even behind a disk drive or battery. On some it's under the
keyboard, because keyboard removal is usually very simple (keyboards are
added at final assembly because they vary by country, so they generally
are easy to remove without full disassembly.

> 3) Where can I get a CMOS battery for this model?

I don't think you can.

Look at
"http://www.mdsbattery.co.uk/departments/department002.asp?Brand=Dell&DepartmentName=Comput er+Clock%2Fcmos+batteries&DepartmentID=141"
where they don't list the 3800, but do sell the batteries for older and
newer Dell models.

> Thanks!
>

On other Toshiba models, the requirement is that the computer is on
(it's ok if the timeout has shut off the LCD screen as long as the
computer itself is still on). This varies by model and manufacturer,
some will charge with the computer off (but plugged into a live
charger). All that can be said is to consult the manual.


BillW50 wrote:

> "Barry Watzman" <WatzmanNOSPAM@neo.rr.com> wrote in message
> news:453E429E.3010802@neo.rr.com
>
>> Leave the laptops plugged in for 24 hours. Most laptops have
>> rechargeable CMOS batteries. On some models, the battery only charges
>> while the laptop is turned on (not simply plugged in, but actually
>> turned on). Of course, this would be a bad design in a machine that
>> won't turn on with a dead CMOS battery.
>
>
> My Toshiba 2595XDVD laptops only charge the CMOS battery whenever the
> backlight is on, according to the manual. This model also sports a
> backup RAM battery (yes a third battery). In both of mine, they are
> dead. But what they do is to allow you to swap the main batteries in
> standby mode (up to 30 minutes of RAM power). Which is a very good idea.
> <grin>
>

Re: "any systems use rechargeable "bridge" batteries, and dispense with
the non-rechargeable lithium coin cell. The bridge batteries allow you
to swap main batteries without turning the system off."

What you call a "bridge battery" is unrelated to the CMOS battery -- two
separate batteries (neither being the "main" battery). Some Toshiba
models that I service has as many as three small internal batteries, in
addition to the main battery, but in Toshiba models two batteries (CMOS
and your "bridge battery") are very common. In all of the Toshiba
models that I have seen (most from 1995 to 2006), Toshiba uses
rechargeable NiMH batteries for the internal batteries. They are not
soldered in place, but rather plug-in, but they are not considered
user-replaceable, either, as some disassembly is required to access
them. Most often, they are located under the keyboard.

SMS wrote:

> vamichael******.com wrote:
>
>> I have two Dell Inspiron 3800 notebooks and am having the same problem
>> on both of them. When I press the "on" button, the LED's for the
>> on/off, caps lock and scroll lock all light up for about 4 seconds,
>> then goes off. The machines never even show the BIOS info screen.
>> These machines have been sitting around for a while unplugged, so I
>> suspect that there is a dead CMOS battery.
>
>
> I assume you tried turning it on without the main battery in.
>
>> My questions are:
>>
>> 1) Does my guess of the CMOS battery being dead sound correct?
>
>
> Unlikely. Remember, when the system is plugged in, or operating from the
> regular battery, the RTC and CMOS are not being powered by the small
> Lithium coin cell battery. M
>
>> 2) Is this something someone handy with a soldering iron could do
>> themselves?
>
>
> It depends where the battery is located. I couldn't find any information
> on this. On some notebooks, it's accessible via a panel on the bottom,
> maybe even behind a disk drive or battery. On some it's under the
> keyboard, because keyboard removal is usually very simple (keyboards are
> added at final assembly because they vary by country, so they generally
> are easy to remove without full disassembly.
>
>> 3) Where can I get a CMOS battery for this model?
>
>
> I don't think you can.
>
> Look at
> "http://www.mdsbattery.co.uk/departments/department002.asp?Brand=Dell&DepartmentName=Comput er+Clock%2Fcmos+batteries&DepartmentID=141"
> where they don't list the 3800, but do sell the batteries for older and
> newer Dell models.
>
>> Thanks!
>>
>

I seem to have a very bad habit of picking up 'new' computers at bargain
prices and saving the newer and using the older. (well...the older
becomes total obsolete faster?)

My Desktops have needed CMOS batteries but they are usually easy to find
and replace. --and buy at a local pharmacy or Wal-Mart or Radio
Shack,etc--


I broke open a Compaq 900mhz laptop about a year ago and the CMOS
battery was FLAT DEAD.

I just broke open (meaning opening box and using for first time) a
Compaq 2135US 1.8ghz.


The clock would not keep time. (when off)


I took it to a computer shop and asked for more ram and to change the
CMOS battery.

This particular shop installs the RAM for a very minor charge. (I've
broken these ram chip holders in past--brittle hold-down plastic clips?)

In past this place has changed laptop CMOS battery also for a very minor
charge. (yet it took them forever to even find it)


After a week I ask the computer shop---where is my computer?

dah....dah...

I drive there. That does it. Ram put in in 52 seconds. CMOS battery? New
people..same shop.... cmos? dah dah... o---that little battery....
ooooo..I checked it....it's still good.....

I say could you not replace it while you have it open to replace? dah
dah...

This place did turn semi-stupid but come to it what is the battery for a
Compaq 2135US?


I can't find it on Compaq website.


The unit is 3++ years old?


Is it really that hard to get at it? I hate to think of springs and odd
hardware that come popping out and never can get together again.

I open a portable am-fm radio to 'tweak' the capacitors and inductors
and can't think of one that I did not screw up.

"internet-terminal zz4" <bb5@webtv.net> wrote in message
news:20316-454601C1-498@storefull-3178.bay.webtv.net

[snip]
> Is it really that hard to get at it? I hate to think of springs and
> odd hardware that come popping out and never can get together again.

CMOS batteries in laptops are not usually hard to replace, just
sometimes hard to get at. They are usually Ni-Cad or Ni-MH batteries.
And they can go completely flat and come right back up when charged (the
computer does this). Although sometimes they don't. So it might not need
replacing.

> I open a portable am-fm radio to 'tweak' the capacitors and inductors
> and can't think of one that I did not screw up.

Hahaha... I did the same thing when I was taking electronics in high
school. Later when I became an electrical engineer, I learned why this
happens. As most of the tweaking coils and caps are for the IF
(intermittent frequency) section. And they are adjusted to pull in all
of the frequencies across the radio band evenly. You start playing
around without special knowledge and equipment, you will more than
likely will change the wide band radio to a very narrow band radio.
Maybe even narrow enough to make it into a one radio station radio.

--
Bill

BUT--if you can't find any battery listing for Compaq 2135US? I guess
try to look for ID on the battery in there.


I think what happened in my present case is I took this thing out of the
box years later and several times first using it 'the clock was off'.
gezzzz Allot of work installing programs on a 'never used computer'.
(and getting rid of junk)

By the time I took it to computer shop maybe the battery DID start
working again. (possible if re-chargable type thing I guess) I have not
had it on again in several days so wait to see.

The MAIN battery is a DEAD weight.



--ok on portable radios... They make such junk now I don't know if you
can find one that picks up a station unless the transmit antenna is
'next door'. Otherwise I'd find they loose sensitivity in time so 'tweak
them'? As mentioned I never had much luck. (except destroy it?


So buy a $5000 laptop and.....


--------open it up with pliers and a hammer trying to change ram and
cmos battery... Where is spring #8,927 ? It bounced out the window and
jumped another mile or so.