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Christina19
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Replaced new cmos battery and got cmos checksum error

Pavilion dv6
Microsoft Windows 7 (64-bit)

My system clock has been losing time and every time I login the power cord it auto start up my computer. I search online they said it may cause by old CMOS battery.  I bring the laptop to the shop that hp refer to, and the shop helps me replace a new CMOS battery, which is provided by their shop.

 

When I turn it on at home, a screen shows:

The CMOS checksum is invalid. The CMOS will be reset to the default configuration and will be rebooted. Please check your BIOS Setup options to see if they change.

CMOS Reset (502)

ENTER - Reboot the system

 

I was frozen and didn’t touch any key when I saw it first time. Then it auto go to login page. I enter password and login window successfully. But when I check the time, it has been set to 2012. I go to synchronize the clock to internet time and get the correct time again. Other driver and software seems has problem so I restart it. Now the system clock is correct and the software looks fine too, I shut down the computer and unplug the power cord without the rechargeable battery like I used to.

 

Next day when I plug-in , the same error page shows, then it makes me think I need to set up something after replacing the CMOS battery, the shop didn’t say I need to set up something after replacing CMOS battery. I search online and go to the bio setting page and set up the time and save it. I login window it shows correct time. But when I unplug the power cord after I turn it off, same error comes up and the bio time setting has been reset to 2012 again.

 

Looks like the “reset” only happen after I unplug the power cord. Before I replace the battery it will only losing time and auto start up when I plug-in the power cord.

 

Can anyone tell me how to fix it? It is the software problem or that battery has problem. I saw an old post said need to install hp support assistant, I did that but it can’t open. I called the shop they suggest me bring back the laptop and let them analyze it over 24 hours. I have many personal data in this computer, if I can fix it by myself I really don’t want to bring it to the shop.

 

Thank you very much

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Replaced new cmos battery and got cmos checksum error

Hi,

Can you provide the exact model or product number of the PC for further help.There are many DV6 models. Here is how to find it:

Model number

 

It sounds like the CMOS battery is not good and needs to be replaced again, or was not inserted correctly. So, the first step would be to replace the battery again and see if the problem persists.

 

When you set the time in BIOS, did you exit saving changes?

 

Let me know,

David

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Christina19
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Replaced new cmos battery and got cmos checksum error

Hi David,

 The model number is dv6-7044TX. And yes, I save the bios before exit. If I didn’t unplug the power cord the setting won’t change. Once I unplug it, it will reset again. I tested yesterday, I didn’t unplug it last night and this morning no CMOs error page shows and the system clock is correct still.

 

should I just go to the shop and ask them check the battery again only? Or I need to backup all my data and let them keep my laptop to test?

 

Thank you. 

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Replaced new cmos battery and got cmos checksum error

Hi,

It is going to be the CMOS battery. I mean, in very rare cases the connector on the motherboard could be damaged. But reading your well-explained case, I am quite sure it is the CMOS battery.

You could actually replace it yourself without too much difficulty if you can find the correct part.

The part number is 682091-001 and you can try performing an online search with the part number to find one.

Example:

https://www.ebay.com/itm/NEW-HP-Compaq-Pavilion-DV7-7047CL-RTC-Bakcup-CMOS-BATTERY-682091-001/112437...

If you look at the battery you can see that it is basically a coin battery that has some plastic around it and a couple of wires. Sometimes technicians will replace only the coin battery inside the plastic housing (about 1 $). However, since yours is not working after going to the technician most likely either the battery they used is already dead or some mistake was made in replacing it. So you could go back to the technician and have the battery replaced again or at least ask for your money back.

 

It is quite an easy process to replace it. You need to remove the main battery which you have probably done on various occasions (you can see on page 46 of the service manual).

Then you need to open the service door by moving the same latch.

service door.PNGopen service door

Next, you remove the RTC battery (CMOS battery) and replace it with the new one. You can see on page 50 of the service manual. it is right next to the hard drive in the corner:

It has a small plug connector that pulls right out.

rtc battery.PNGCMOS battery

 

Service manual:

http://h10032.www1.hp.com/ctg/Manual/c03582006

 

Hope it helps,

David

 

Christina19
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Replaced new cmos battery and got cmos checksum error

They didn’t give me back my old CMOs battery last time ( at least my old CMOs battery won’t show that error), so I guess I can only go back to the shop ask them replace it again. 

Thank you for the manual link. It helps a lot.

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Replaced new cmos battery and got cmos checksum error

You're welcome.

Let me know how it works out after replacing the battery again 🙂

 

All the best,

David

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