CMOS battery also know as RTC battery
Any laptop computer has a CMOS battery also known as RTC battery. The CMOS battery connects directly to the laptop system board and helps to retain important BIOS settings such as system time, date, BIOS configuration while the laptop is turned off or even when the main battery is removed.
The CMOS battery is rechargeable and it’s getting charged when the laptop is plugged into the mains.
CMOS batteries come in different shapes ans sizes.
On the picture below you see a basic coin cell CMOS battery. This type of batteries usually found in older laptops. This battery is removable and replaceable.
Here’s another type of CMOS battery. Basically, it’s two coin cell batteries but they are bundled together and have a cable which plugs into the system board. This battery is removable and replaceable.
On the next picture you see a CMOS battery which is soldered to the system board. In order to replace this type of battery, you’ll have to unsolder it from the system board.
CMOS BATTERY LOCATION IN A LAPTOP.
In some laptops the CMOS battery could be easily accessed from the bottom, as it shown on the picture below. As an example I took a Dell Inspiron 1720.
In some laptops the CMOS battery is hidden under the keyboard. As an example I took a HP Compaq nc6400 laptop.
Here’s the worst case scenario. The CMOS battery is hidden under the laptop cover. In order to access and replace the battery you’ll have to disassemble the whole laptop. As an example I took a Toshiba Satellite A305 laptop.
CMOS BATTERY RELATED PROBLEMS.
Here’s the most common problem related to the CMOS battery.
Each time you turn off the laptop it resets date and time back to factory defaults. When you turn the laptop back on it asks you to set date and time. If that’s the case, most likely your CMOS battery is old and has to be replaced.
By the way, removing the CMOS battery on most newer laptops will not clear the BIOS password.
Need spare parts for your laptop?
If you are looking for spare parts for your laptop you can find brand new and used parts here. Just search by the part name and laptop model.
December 29th, 2008 at 9:35 am
My laptop will not start at all. When I press the power button nothing happens. Do you think the CMOS battery is dead?
December 29th, 2008 at 10:13 am
Serge,
I don’t think so. From my experience I can tell that your laptop should start even if the CMOS battery is removed.
Without CMOS battery you will not be able to save settings (date, time, etc…) but the laptop should start.
Check the AC adapter. It’s possible that your adapter is dead and the battery discharged. You can test your adapter with a voltmeter. Make sure it outputs correct voltage.
January 1st, 2009 at 12:04 pm
Hi Repair Man. I opened all covers on the laptop and even removed keyboard. I cannot find the battery anywhere. Maybe my laptop doesn’t require one?
January 1st, 2009 at 1:50 pm
Debra T,
Nope, there must be a battery somewhere. I guess it’s buried somewhere inside the laptop and you just cannot find it.
January 2nd, 2009 at 3:16 pm
I found the battery!!!
It was under the laptop cover.
January 3rd, 2009 at 3:26 pm
Man! Searched everywhere and couldn’t find CMOS battery for my Sony notebook. Finally found it at PCHub. No time and date resets anymore!
January 9th, 2009 at 8:53 am
one day my 1year old toshiba started asking for a paassword but i never had a password. i cannog start windows. can i clean the password? do i have to replace cmos battery?
January 9th, 2009 at 10:06 pm
alan,
I know that some newer Toshiba laptops can set the BIOS password on its own. Check out this Toshiba support bulletin, it’s related to your problem.
Toshiba will clear the BIOS password on some Satellite A100, A105, A135, A205, L35, M200, P100, P105, P205 laptops at no charge even if your laptop is not under warranty anymore.
January 12th, 2009 at 11:10 pm
I had a password on my HP laptop. I cannot clear the password. I tried everything. I removed the main battery and CMOS battery for 1 day and the password is still there.
Probably have to send it to HP now.
Does anyone know how to remove BIOS password on HP laptops?
January 13th, 2009 at 2:16 pm
charlotte,
On most newer laptops you cannot erase the password by removing the CMOS battery. I think you’ll have to contact HP customer service and see if they can help you.
February 19th, 2009 at 11:06 am
I have a soldered-on RTC battery on a toshiba satellite m115 and would appreciate a detailed description of how to replace it.
Please help!
February 19th, 2009 at 4:56 pm
hi, im glad to read that im not the only one who cant find the cmos battery, i have tried to dis assemble the case so i can take a look inside but cant get it off, my laptop is a tosh a210-171. where can i find instructions to do this.
many thanks.
ps, already searched tosh`s website
February 24th, 2009 at 8:19 pm
Hoban1962,
What is your reason for replacing the RTC battery?
If you are trying to clear the BIOS password, replacing/resoldering the battery is not going to help.
How exactly do you want me to help you? If the battery is bad, you simply unsolder the old one and replace it with a new one (if you can find it).
February 24th, 2009 at 8:24 pm
garry,
In a Toshiba Satellite A210/A215 the CMOS battery is soldered to the motherboard. You’ll find some disassembly instructions at http://www.irisvista.com/tech/
If you cannot find your particular model, search for similar models.
By the way, as I mentioned in the previous comment, removing the CMOS battery in this model will not help you to clear the BIOS password.
Is it your reason for accessing the battery?
Some newer Toshiba laptop can set the BIOS password on its own. You’ll find more information in this post.
March 2nd, 2009 at 5:04 pm
I have a Toshiba L15-104, and I am experiencing no boot up. The HDD spins, a few lights flash, but the screen does not turn on. I recently bought a battery, and charged it. I have been told that the CMOS battery could be dead. I took apart the laptop twice, trying to find anything that resembles a battery or wires attached to a battery. No luck, I did discover, a plug that is not in use that is white with 2 leads that could connect to it.
This is about a 5 yr old system. I took it into repair a year ago, and am wondering if they “neglected” to replace the CMOS battery. I no longer have the warranty on it. Any help, please. Or the part number for this battery.
March 3rd, 2009 at 7:30 am
My Toshiba satellite M40X stop afer 3 or 4 mn….every time i put it on , it stop again (black screen, no message…) and i need to wait 1 hour then i can start it again, then it stop after 3 mn.
I hav verify ther is no heat, the computer is well cold…
I have oppened it to change the cmos battery, but i didnt find it.
My computer is 5 yrs old.
Thanks
March 3rd, 2009 at 8:54 am
Dizteck,
I don’t think that your problem is related to the CMOS battery.
From my experience I can tell that your laptop should start even if the CMOS battery is completely dead or missing. With a bad CMOS battery you cannot save BIOS settings but it shouldn’t prevent the laptop from booting into Windows. If you set date/time or change settings in the BIOS, they will be reset back to defaults on the next reboot.
Most likely the CMOS battery is soldered to the motherboard, as is done on many newer Toshiba laptops. As an example, take a look at the third picture.
Does it sound like the laptop is working fine except the screen? Can you test the laptop with an external monitor? Can you get video on the external monitor at all?
If both the internal and external monitor do not work, your problem could be related to the memory module. How many memory modules do you have installed?
If you have only one module, try reseating it. Try installing it into the empty slot.
If you have two modules installed, try removing them from the laptop one by one. Test your laptop with each module separately.
March 3rd, 2009 at 9:09 am
bruno645,
What exactly it’s doing? Can you see the Toshiba logo on the screen? Will it start loading Windows and then dies?
I believe your Satellite M40X is similar to a Satellite M35X in which the CMOS battery is soldered to the motherboard. I really doubt that replacing the CMOS battery will help to fix the problem.
You can troubleshoot the problem as it explained in this article:
Laptop is dead. How to troubleshoot the problem.
The laptop in that article should be similar to your laptop.
March 3rd, 2009 at 11:16 am
I have 2 memory chips, I had taken the laptop apart 2 times, resetting everything that was removed. Like I mentioned, I don’t see the screen light up nor do I see all the lights light up. On a normal boot, I would have seen the screen go to windows start, the light for the WiFi on the front would light up–that’s on a normal boot. But, for some reason, when I turned on the laptop the next day it experienced what I mentioned. Push on button, lights flash normally, HD spins, then stops with no monitor activity. I tried plugging in an external monitor, but with this Toshiba, I would have to press the Function Key and another key to toggle between outputs. My final assumption is that, either the Motherboard has failed but, I understood it was replaced one year ago, included in the warranty.
March 3rd, 2009 at 11:37 am
Dizteck,
I believe that if you start the laptop with an external monitor already connected to the VGA port, you don’t have to use the function key. The external monitor should be detected automatically. If you cannot get any video on the external monitor, apparently there is no video signal coming from the motherboard.
I guess your assumption is correct, you have a failed motherboard.
March 14th, 2009 at 5:05 am
Repairman,
I have a HP NX9110 that is locked down with a BIOS password. I have contacted HP in regards to this matter, only to find out that at a considerable cost, they will fix it. The cost was astronomical, it was more beneficial to go and by a new laptop, so I did *Smiles. So I naturally I have a doorstop, that is sitting there, now at this stage I have disassembled the NX9110, and I am wondering if it is salvagable, by either shorting the battery out, or using the jumpers to reconfigure this computer, or even flashing the bios completely. As this is a later model, I am wondering if tinkering with it, will reborn this doorstop again, your guidance on this matter would be greatly appreciated.
March 15th, 2009 at 1:49 pm
Jase,
I don’t know if it’s possible to clear the BIOS password on this model via jumpers, HP doesn’t share that information. I really doubt that removing the CMOS battery will help you.
I guess the only way to make it work again is replacing the motherboard. You can find a new motherboard by the HP part number. Usually the part number could be found on a sticker by the memory slot.
Also, search for HP BIOS password on ebay. Looks like some people offer BIOS password removal services.
March 17th, 2009 at 7:12 am
Hi! I’ve got a toshiba satellite p100-227. It appears that the rtc battery is the problem. I have updated bios, checked conflicts etc, but to no gain. Everytime i change time/date (f2 during boot), it remains that way after restart. The computer is about 2,5 years old, (is it normal to have to change battery after only two years?) However i did remove the main batteryback for about a month to save it from going bad, then reincerted it(computer was connected to mains all the time). Can this be the reason the rtc has gone sour on me so fast?! Is there any possibility that it will recharge? Do you have a oem partnumber for this battery? Great site btw!
March 17th, 2009 at 9:52 pm
johan,
I think it should last longer. I see a lot of different laptops every day. Some of them are over 5 years old with a good working original CMOS battery.
Definitely. Plug in the main battery and charge it overnight. Most likely your CMOS battery will recharge too.
March 18th, 2009 at 1:28 am
Repairman, I’ve read a thread at the toshiba forum about this problem. Some people had the same prob. One guy sent his p100 for fixing and what they did was to remove the rtc for a while and then reincerting it, this did the trick. My warranty has expired and i found a great step-by step instruction on how to get to that little bugger, so i’ll go ahead and try this. BTW. yesterday i experienced that the clock doesn’t even work properly while computer is on; it was reset in bios at 20,25 and after several hours it was showing 20,48, so it “jumps” back to 20,25, but never before 20,25! It works a couple of hours, tops, and then resets, weird… I’ll let you know how it went!!
April 27th, 2009 at 11:46 pm
I’m also a computer technician, and i found your website very informative, it adds up my knowledge about computer repair, most especially laptops
May 8th, 2009 at 1:26 pm
Hi. Please does anyone know the specifications of the RTC/CMOS battery ML1220 of the Toshiba Satellite A135?
I know that is is 3V, but I have no idea about mAh, if 15 or 36mAh or what?
If anyone knows, please let me know.
Thanks.
May 8th, 2009 at 1:32 pm
Aza,
I think this battery is 15mAh. Check out this specifications for Sanyo Lithium Cell Type ML1220. Hope it helps.
May 19th, 2009 at 12:33 pm
I HAVE ACCER TRAVELMATE C300 I have a HP NX9110 that is locked down with a BIOS password. how i can remove passowor howi can enter BOISE PLS HELP ME
June 5th, 2009 at 6:06 pm
http://forums.pcper.com/showthread.php?t=464536
I’m trying to get rid of this bios password on this unknown toshiba satellite laptop. I first unplugged the power connector for 15 seconds. Booted it up and the password stayed. I then unpluged wall power, then unplugged the bios battery connector for 3 minutes. Now the computer won’t boot? The power button doesn’t power it on? Any ideas? Help would be high appreciated.
June 5th, 2009 at 6:18 pm
Chris,
If you have an older Toshiba laptop this parallel plug should clear the BIOS password.
June 10th, 2009 at 5:54 pm
hi i have a lenovo laptop and im trying to remove the bios password and cmos password and i was wondering weather u could help me
June 16th, 2009 at 1:12 pm
I just bought a used HP Compaq NC6400 and it needs to have the CMOS battery replaced. What do I need to do?
June 16th, 2009 at 1:17 pm
Rebekah,
In a HP Compaq nc6400 the CMOS battery is located right under the keyboard, so you’ll have to replace the keyboard as it explained in this guide: How to remove keyboard and replace memory in HP Compaq nc6400 laptop. You can see the CMOS battery on the 5th picture, right above the memory modules.
1. Find and buy a new CMOS battery.
2. Remove laptop keyboard.
3. Unplug the old battery and replace it with a new one.
July 7th, 2009 at 10:58 am
Need to replace the battery on my packard bell easynote F7305 laptop cannot get it out is there a special way to remove it please
July 9th, 2009 at 9:44 pm
have a inspiron 600m laptop and its not keeping the correct year (it is saying 2002). It was keeping the year perfectly before. When I checked the location of where the reserved battery was there was none. I’m a bit confused because the reserved battery (aka CMOS battery) is not there…but the laptop use to keep the year. What must i do? thanx.
July 10th, 2009 at 9:02 am
cb,
Most likely you have bad CMOS battery.
I don’t know why it happens. Maybe you are looking for the CMOS battery in the wrong place?
Install the CMOS battery. Set time and save the settings.
July 15th, 2009 at 12:45 pm
On what i new when system was passworded and accidentally the owner forgot the password by removing the CMOS battery you con retrieve the system back.
but with the introduction of the new laptops am were limited to unblock password,
WHAT SHOULD I DO???????????????????????
July 16th, 2009 at 10:14 pm
Abdul aziz sanin baba,
It worked on some older laptops. Will not work with newer laptops.
Take your laptop to the authorized repair center. It’s not free but most likely they can help (unless it’s an IBM laptop).
July 17th, 2009 at 2:56 pm
Need a Schematic: Toshiba Qosmio F20. Model: PQF20L-00L00H.
Bought while on R&R from Iraq. Went to Thailand! Have had since 7/06 without any problems untill daughter had spilled a coke upon the Keyboard!
Awaiting New Keyboard & CMOS Battery. Plan to Upgrade & could use the schematic!
Thanks,
Bill
July 17th, 2009 at 10:09 pm
billh,
Take a look at this disassembly guide for a Toshiba Qosmio F25. Could be very similar to your Qosmio F20.
July 24th, 2009 at 5:55 am
We were discussing this over at the TechSupport Forums adn this post was pointed out. You mention that the RTC battery isthe CMOS battery – I understand this is not the case in all Laptops – they may have an DTC rechargable and a CAP or Flash Module to act as the CMOS Battery. This is due to the lowering voltages needed by the components on the MB – including the CMOS.
I happen to have an issue i’m attempting to trouble shoot – i noticed the time in the Bios does not keep time. But, not sure it it relates to the CMOS or if it does since i do not know if there is indeed a second soldered component acting as the CMOS battery (CAP or Flash) – my sytem OS keeps the correct time. IS it possible or one of the symptoms of a degrading Lythium RTC battery to cause restore issues or software running issues. My particualr issue is it seemingly starts to slow down to a freeze. After running tests known of my hardware aside from the lythium battery show fault or errors.
With todays comps – adn the possibility of teh dual RTC battery and other CMOS CAP or Flash – what are the symtoms caused by a bad RTC BAttery other than the time being incorrect in the bios? And how do you know if you have the Dual battery/CAP? Most Manufacturors will not give up service manuals which show components soldered to the MB.
July 24th, 2009 at 4:11 pm
plz
can u help me
where is the coms battery in toshiba A100 satllite ??
ana how can i remove it ?
July 25th, 2009 at 9:16 pm
egyptian,
The CMOS battery is soldered to the motherboard. Take a look at this picture (motherboard from Satellite A105). You’ll see the CMOS battery on the right side from the circled screw.
By the way, removing the CMOS battery will not clear the BIOS password. If it’s your reason, don’t even try.
August 19th, 2009 at 5:36 pm
the rtc battery went flat on my acer travelmate 520, and
as well as the date and time being lost, it also did
something to the graphics settings. I put a new battery in
and although the laptop works again, The acer welcome screen
(red satchel)is too big, when the laptop boots up the windows desktop is too big
(can’t see the start menu and systray)
If you hook up an external monitor that’s fine!
when this model was new, it was available with a range of screen sizes from 12.1″(mine)up to 14.1″. it’s almost as if it thinks it’s got the 14.1″ screen attached to it. According to acer
all models run the same motherboard, so how does the laptop “know”
how big its attached screen is?
I’m going slowly mad………
August 19th, 2009 at 8:19 pm
Tank,
Enter the BIOS setup menu and try loading default settings, there should be a button for that. After that save it and reboot the laptop. Not sure if it’s going to help but you can try.
September 12th, 2009 at 6:16 am
hai,,,im facing a big problem…my buffalo network adapter is not working..there is 2 PCMCIA slots in ma laptop..and wen i insert the adapter to the top slot ,laptop detects the network card but after installing the driver ,it says cannot start the device..and wen i insert it to the bottom slot..my xp gets stuck..my xp continues working if i remove the adapter from the slot..what should i do..im not able to use ma wireless these days…i am using IBM T21..
September 13th, 2009 at 10:26 pm
bhagynath,
Not sure what’s going on but it’s possible you have some kind of compatibility issue between the PCMCIA card and your ThinkPad laptop.
I know that ThinkPads might now work properly with some internal Wi-Fi cards because it has to be some kind of “IBM certified card” or something like that. Apparently, the same applies to some external PCMCIA cards.
Can you find another PCMCIA Wi-Fi card for test?
September 18th, 2009 at 9:41 pm
how to delete the bios password?
September 28th, 2009 at 4:23 am
Think Maxdata CMOS battery to M350 Vision model with PhoenixNoteBios under keyboard is hidden in the back under screen hinge. Red & black wiring plus connector can be seen, and by lifting upper casing becomes visible in a spacing. Yet, battery underneath, requiring to lodge the part underneath the screen. The connector can thus be easily disconnected, but battery needs extra operations to gain access to.
September 29th, 2009 at 10:45 pm
Toshiba satellite M40X-148 cmos battery located under hardisk metal housing (the other side of motherboard). need to remove 4 screw tighten the metal housing (actually need to unassembled all parts & screw). it is soldered to the motherboard. need to flip the motherboard. half covered with blue plastic. short using wire the two solder for 15 minute and the bios password is reset. useful when u forgot the password.
October 1st, 2009 at 12:39 pm
ronin,
Have you tried that yourself?
I believe removing the CMOS battery will not clear the BIOS password on newer laptops.
October 16th, 2009 at 8:32 pm
I need to replace a battery that is encased in plastic just like the 3rd example (Dell). Can I buy the battery alone, or do I need to find the entire assembly – enclosed battery +cables+connector?
this is for an acer 9410.
October 17th, 2009 at 6:40 pm
NovaScotiaMika,
I doubt that you can find just the battery alone. I think you’ll have to find and purchase the entire assembly.
October 17th, 2009 at 10:43 pm
i have toshiba tecra a6. my laptop time isn’ running, i’ve checked the BIOS and it’ not running too. maybe i have a problem with cmos battery
do you know where the CMOS battery is?
and how can i remove it?
October 17th, 2009 at 10:51 pm
john,
I believe in a Tecra A6 laptop the CMOS battery is soldered directly to the motherboard. Take a look at this guide for a Satellite M105 notebook. It has same body as Tecra A6.
In the step 22 there is a picture when the top cover is removed. On the bottom of the motherboard there is a square Intel chip. A little bit lower you’ll see the CMOS battery, it’s blue. Same as on 3rd or 6th photo in my post.
October 18th, 2009 at 6:53 am
Hi
I have a Acer Travelmate 4000 ZL1. Is there a guide so I can easily disassemble the laptop so i can get to my CMOS battery. Much appreciated.
Mario
October 18th, 2009 at 6:58 am
Furthermore to my question. Can i use a CMOS battery from a Travelmate 3000 on my 4000?
October 18th, 2009 at 8:46 am
Hi,
I have a Acer Travelmate 4000 LZ1. I would like to know how to disassemble the laptop to get to the CMOS battery. Also would a Travelmate 3000 CMOS work in my Travelmate 4000.
I would like a service manual for a Dell Latitude C540/C64o laptop.
Your help is greatly appreciated.
Mario
October 27th, 2009 at 8:07 am
Mario,
Take a look at this disassembly guide for a Acer TravelMate 3260 laptop, could be similar to your laptop.
By the way, it this model you can access the CMOS battery through the door on the bottom. It’s located close to the wireless card. Take a look at the picture in the step 10, it shows the battery.
I don’t know. Find the battery, remove if from the laptop, find the part number on the battery and google it.
November 3rd, 2009 at 10:41 pm
Toshiba PRO L40
Hi there,
After a bios update computer rebooted fine into windows. I then restarted and went into bios to save settings.
Computer performed reboot but gave black screen syndrome. I think a bios reset is required. The laptop has been stripped to locate the soldered CMOS battery and now I was hoping for information to perform a manual reset.
Thanks in advance.
November 4th, 2009 at 1:59 am
Toshiba PRO L40
Update
I was under the impression that since after WinXP BIOS update, the laptop had initially rebooted, passed BIOS, entered WinXP and after the second reboot and attempted save of BIOS, a simple BIOS reset to default was necessary.
(Summary WINXP_BIOS_UPDATE > REBOOT > WINXP > RESTART > ENTER_BIOS_TO_SAVE_DEFAULT > REBOOT > BLACK_SCREEN)
1.The laptop was dismantled with help from the excellent guide:
http://www.irisvista.com/tech/laptops/Toshiba-Satellite-L45/laptop-disassembly-instructions-1.htm
2. The CMOS battery was located and a small piece of solder was placed across battery wires connected to motherboard and left for fifteen minutes, in order to create a short and therefore force a BIOS default reset.
This was a success.
The BIOS was AMI based.
I hope someone, somewhere finds this information helpful, as it took me a full day to resolve this problem.
Regards.
Thanks.
November 4th, 2009 at 6:05 am
notuagain,
Thank you for your comment. I wasn’t aware that shoring the CMOS battery this way will fix the problem. I’ll try that when I have a chance.
Also, thanks for finding my guide for taking apart a Satellite L45 laptop.
November 4th, 2009 at 8:19 am
Hey there RM, thanks for the sites they sure helped me out!
The battery definitely was drained through the short as ‘LOW CMOS BATTERY’ was displayed in BIOS upon successful boot and BIOS was altered to its default state.
December 22nd, 2009 at 12:12 pm
Hi
Anyone knows were’s located the onboard soldered cmos battery on Texas Intruments EXTENSA 600? It’s a really old laptop from 98…would be great if i could revive it. Dead cmos message on the startup screen.
Thanks
January 3rd, 2010 at 5:59 am
Hi Pedro, the CMOS battery of the Extensa 600 is located behind the Parallel Port Connector. It’s on the front side of the mainboar. You have to completely disassemble the laptop. The battery is NimH 3.6 V /40mAh and is soldered on the mainboard (1cell). It can’t be seen because it’s hidden under the metal frame of the laptop. Basically
on the right of the Display connector … search for the service manual of the Acer Extensa 600 named ‘extensa 600 650.PDF’ for easier disassebmly. Good luck ! … it took us 2 days to find it … finally found it this night … it was a nightmare
January 4th, 2010 at 4:24 pm
HI there Thanks for the info man! I was looking long time the location of it…it’s really hidden hehe
Next week i’ll do it and post results then.
January 15th, 2010 at 12:24 am
Is there a way to reset the bios password on the satellite a215-s5825? ( I do not see this model listed on http://www.insidemylaptop.com/my-toshiba-laptop-displays-password-prompt-on-startup/ ) And i saw mentioned “By the way, as I mentioned in the previous comment, removing the CMOS battery in this model will not help you to clear the BIOS password.”
If removing the battery does not reset it, is there a method i can use to do it? any jumper settings that may get it done? or anything?
thanks in advance
January 15th, 2010 at 11:50 am
Whats the Number of this Bios Battery??
http://www.laptopparts101.com/wp-content/uploads/2008/12/cmos-battery-under-top-cover-560×420.jpg
January 19th, 2010 at 11:29 pm
Michael,
I believe it’s Sanyo ML1220 rechargeable battery. Used in many newer Toshiba laptops.
January 19th, 2010 at 11:38 pm
the lost ranger,
If the BIOS password was set by the laptop, call Toshiba and explain what’s going on. Most likely they will clear the password at no charge.
The password is cleared by shorting two contacts on the motherboard. I cannot tell you more. If it’s your laptop and registered on your name, call Toshiba and most likely they will help you.
January 26th, 2010 at 1:34 pm
Where can i find the Cmos on the compaq presario r3000?
I need to bypass a bios password.
Is there an other backdoor to compaq notebooks other than “compaq”?
Thanx in advance
January 27th, 2010 at 2:36 pm
Lux,
I’m not sure if disconnecting the CMOS battery will help to get rid of the BIOS password. Maybe you can find this info in the service manual for Compaq Presario R3000 notebooks here: http://h10032.www1.hp.com/ctg/Manual/c00212209.pdf
February 22nd, 2010 at 11:31 am
HI,I have a Toshiba Satelite M45 S165 laptop(5 years), and I think I a have a Cmos batery problem. It all started 1 year ago when the time keep falling behind. 2 days ago I took out the main battery, and after that the laptop woudnt start again. If I manage to enter BIOS, the time is freezing after 3 second, and nothing,I have to unplug the AC, and take out the main Batery to shutdown the laptop. I think the problem is the Cmos batery, which is soldered to the MB.
I dont know what tipe is it, and where to buy a new one.
Sr for my eng. Please help me.Tx.
February 22nd, 2010 at 12:03 pm
delu,
I don’t have this motherboard and cannot confirm what CMOS battery it has, but I believe that Panasonic ML1220 might work.
Google for Panasonic ML1220 and you’ll find it. I found this battery on another Toshiba motherboard and it looks similar to one installed in a Satellite M45.
March 8th, 2010 at 6:41 pm
I have the Toshiba Satellite A305 laptop as shown above. Can you short this the battery and how would you go about doing it? If not and I remove the battery will I have to re-solder it?
March 10th, 2010 at 12:35 pm
A common small trap some people are unaware of, some soldered Cmos Batteries run at 1.8V and not the standard 3.3V of a CR2032 this is just one thing to be aware of. So take it to a watch maker as mine was a small brown cell and the shop assistant was able to hand me an exact replica of it.
Sadly good help is like a needle in a haystack and everybody things their a pro. `not getting at anyone on this site btw’
Quote from another site “my laptop does not work it has a blank screen powers up and dies”.
A typical time wasting answer to that is something like “have you tried the recovery disks” it really makes me want to scream when people don’t read the question properly. What possible use are the recovery disks if its CMOS battery or chip has possibly died!
EEprom blower!!!!!!
I will hasen to add that a dead Acer 1800 battery brought me here
March 10th, 2010 at 10:22 pm
MR Blogs,
All motherboards are different.
For example, in most newer Toshiba laptops CMOS batteries run at 3.0V (here’s an example http://batteries.sanyo-component.com/fileadmin/EDITORS/BATTERIES/industrial/datasheets/lithium/ML1220.pdf)
LOL!
How can you run the recovery disc if the laptop is dead???
By the way, in the above mentioned scenario I would check the AC adapter first and RAM modules after that. It’s possible one of the modules is bad.