Replace CMOS Battery

Soccer Ball

Suspended
Joined
Apr 7, 2015
Messages
9,859
Reaction score
3,510
I suspect my CMOS battery is giving me problem.
Sometimes starts PC nothing, screen black black. Needs a few try to boot to windows.

Can I just replace it with a new battery without setting anything?
 

sadboy

Master Member
Joined
Nov 24, 2000
Messages
2,916
Reaction score
179
Once you removed the battery the bios setting would revert back to factory default. So... If you didn't configure a lot or change the bios setting you are safe.

But usually a weak battery would give revert your system back to default date and time sort of error.

Blank screen sound like hw issue.
 

yusoffb01

Arch-Supremacy Member
Joined
Jun 17, 2008
Messages
16,814
Reaction score
1,769
you can try... but even with dead or no battery, it should not have any problems.

Your issue could be psu or motherboard
 

commach

Great Supremacy Member
Joined
Apr 11, 2001
Messages
53,997
Reaction score
18
If you want to replace CMOS battery without affecting the BIOS setting, do it when the system is running. This is the default method for CMOS battery change for all CNC machines. If a ignorant machinist take out the battery when the machine is power down, the machine will never be able to run normally again without configuring the perimeter to match the factory and customise setting.

If the battery already dead, the CMOS setting already revert to default setting, doesn't matter anymore how you change the battery.
 

produde1999

Master Member
Joined
Mar 18, 2013
Messages
2,896
Reaction score
16
cmos battery causes issue only like windows time suddenly become 2009. bios setting always back to factory setting once you main power off pc.

it would not cause issue like cannot boot.
 

commach

Great Supremacy Member
Joined
Apr 11, 2001
Messages
53,997
Reaction score
18
cmos battery causes issue only like windows time suddenly become 2009. bios setting always back to factory setting once you main power off pc.

it would not cause issue like cannot boot.

Wrong, BIOS/CMOS setting will not go back to default setting with a working battery even if you unplug the power cord from the power supply. Only with a dead CMOS battery, the setting will revert to default setting when external power source removed.
 

sadboy

Master Member
Joined
Nov 24, 2000
Messages
2,916
Reaction score
179
Wrong, BIOS/CMOS setting will not go back to default setting with a working battery even if you unplug the power cord from the power supply. Only with a dead CMOS battery, the setting will revert to default setting when external power source removed.


Yah this only happens with a dead or weak battery. The whole idea for the battery is keep date/time running + CMOS configuration settings
 

joshuaho

Senior Member
Joined
Jan 3, 2015
Messages
830
Reaction score
0
I think he meant with a dead battery and powering off the mains._. For TS case, sounds like a MOBO or PSU issue though with the booting problems

Wrong, BIOS/CMOS setting will not go back to default setting with a working battery even if you unplug the power cord from the power supply. Only with a dead CMOS battery, the setting will revert to default setting when external power source removed.
 

Soccer Ball

Suspended
Joined
Apr 7, 2015
Messages
9,859
Reaction score
3,510
I think he meant with a dead battery and powering off the mains._. For TS case, sounds like a MOBO or PSU issue though with the booting problems



How to know if it's mobo or psu. My PC sometimes can power on but screen nothing cannot boot to windows. Need to off and on again until it does. Sometimes power on halfway reboot again.

Please advice. Thank you
 

Apex

Master Member
Joined
Jan 1, 2000
Messages
2,510
Reaction score
251
How to know if it's mobo or psu. My PC sometimes can power on but screen nothing cannot boot to windows. Need to off and on again until it does. Sometimes power on halfway reboot again.

Please advice. Thank you

Sometimes power on halfway reboot again.

This sound like an HW issue.

Maybe can start of listing the hardware you have?

CPU, Motherboard, GPU and how old is your pc
 

produde1999

Master Member
Joined
Mar 18, 2013
Messages
2,896
Reaction score
16
I think he meant with a dead battery and powering off the mains._. For TS case, sounds like a MOBO or PSU issue though with the booting problems


right on.

How to know if it's mobo or psu. My PC sometimes can power on but screen nothing cannot boot to windows. Need to off and on again until it does. Sometimes power on halfway reboot again.

Please advice. Thank you
do you hear beeps when can't boot. if u do hear, tell us how many long beep and short beep.

Do you cant boot to windows only or bios also jialat?

if always can boot bios no issue, it might be windows need factory reset or hdd dying liao.

if lazy check, just change psu. mobo rarely dies but psu got fan and stuff normally die earlier than mobo.
 
Last edited:

Soccer Ball

Suspended
Joined
Apr 7, 2015
Messages
9,859
Reaction score
3,510
Sometimes power on halfway reboot again.

This sound like an HW issue.

Maybe can start of listing the hardware you have?

CPU, Motherboard, GPU and how old is your pc

i5 4690
Asrock B85 killer
Zotac 750 Ti OC 2GB
seasonic s12ii 520

PC was built in 2014
 

wwenze

Greater Supremacy Member
Joined
Dec 2, 2002
Messages
86,463
Reaction score
30,152
-asrock
-from 80 series era

Does it act like this when it is powered up but not booting?

 

wwenze

Greater Supremacy Member
Joined
Dec 2, 2002
Messages
86,463
Reaction score
30,152
The next time you manage to boot into Windows, update the BIOS.

And do it ASAP because your chance of success decreases by the day.

Oh remember to reset CMOS fully after reflashing the BIOS.
 

Soccer Ball

Suspended
Joined
Apr 7, 2015
Messages
9,859
Reaction score
3,510
The next time you manage to boot into Windows, update the BIOS.

And do it ASAP because your chance of success decreases by the day.

Oh remember to reset CMOS fully after reflashing the BIOS.

Just did. Still same problem:(
 

joshuaho

Senior Member
Joined
Jan 3, 2015
Messages
830
Reaction score
0
Both require some form of tools, but I would say PSU is easier to test.. if you have volt meters and stuff. But ofc if you are not sure just go get new parts and forget about it, don’t want any incidents of injury.

What mobo and PSU are u using? And how Long have you been using? If more than 5 years can just consider buying new PSU Liao lor. Mobo really depends.. so far mobo kaput quite rare for me ley, usually is the movable parts such as PCIe slot or dimm slot that breaks down for me first due to mishandling.

How to know if it's mobo or psu. My PC sometimes can power on but screen nothing cannot boot to windows. Need to off and on again until it does. Sometimes power on halfway reboot again.

Please advice. Thank you
 

IcYFl4mEz

Arch-Supremacy Member
Joined
Jul 28, 2004
Messages
15,731
Reaction score
485
Maybe same as mine old pc prob. Pc keep restart n cant boot.
Change the mobo n it works.
 

Soccer Ball

Suspended
Joined
Apr 7, 2015
Messages
9,859
Reaction score
3,510
do you hear beeps when can't boot. if u do hear, tell us how many long beep and short beep.

Do you cant boot to windows only or bios also jialat?

if always can boot bios no issue, it might be windows need factory reset or hdd dying liao.

if lazy check, just change psu. mobo rarely dies but psu got fan and stuff normally die earlier than mobo.

Sometimes it just power off and on again without loading anything.

Sometimes can load bios. But most of the time just hanged.

I suspected now it's mobo. Cause after load windows sometimes I see 16gb ram, sometimes 8gb ram.

Please advice if I need to purchase back same model MOBO?

Thank you
 
Important Forum Advisory Note
This forum is moderated by volunteer moderators who will react only to members' feedback on posts. Moderators are not employees or representatives of HWZ Forums. Forum members and moderators are responsible for their own posts. Please refer to our Community Guidelines and Standards and Terms and Conditions for more information.
Top