2 Intern
•
47 Posts
•
83 Points
0
185
July 16th, 2026 03:37
CMOS battery replaced on Vosto 3470 Desktop PC but BIOS settings are not retained after shutdown
I have replaced the CMOS battery two days ago with a new one, but when I bootup the PC after a few hours it does not boot properly. The power-on button glows briefly and stays dim for few seconds and then restarts bootup, this happens in a loop and I have to keep the power button pressed for a minute or so to end this process. Then press power button and F12 key to end BIOS Setup to check for what is causing this issue. Noticed that BIOS settings are set to default and the Date & Time are set to 31-Aug-2023, perhaps the last BIOS upgrade date (BIOS is latest version, i.e. 2.33.0). After I change the date and time and exit BIOS Setup after the PC reboots, it loads Windows 11 properly and works fine in Windows environment for that session. But, once I shutdown the PC and bootup afresh after a few hours / next day, the same process repeats. Can someone guide me on what could be the issue and whether this indicates an imminent motherboard crash ? I have made no hardware changes to the PC recently.
Any inputs to resolve this issue would be much appreciated. TIA
Ramesh Iyer
2 Intern
•
47 Posts
•
83 Points
0
July 25th, 2026 03:50
Thanks for your inputs folks. Been away for a while. Yesterday I removed the battery and reinstalled it after 15 minutes or so, while keeping the PC switched off. Somehow, this time it has worked and issue hasn't recurred after I have shutdown & restarted the PC few times. Perhaps issue arose due to the new battery being loose in the slot.
bradthetechnut
9 Technologist
•
9.6K Posts
•
40.6K Points
0
July 16th, 2026 04:27
Test the battery and make sure it isn't bad. I highly suggest Energizer batteries. They last a long time and don't leak. Also, make sure the battery is inserted correctly.
If the battery is good, do a BIOS reset via the blue jumper method that I mentioned in your other thread.
Ramesh Iyer
2 Intern
•
47 Posts
•
83 Points
0
July 16th, 2026 05:41
@bradthetechnut Yes, I did. I have another small device which operates on two CR2032 batteries and when I inserted these Duracell batteries (new ones off the pack) that device works fine, so don't think the battery is bad. I don't have a multimeter to test the batteries though.
Also, I waited 5-10 minutes before replacing the battery (as mentioned in the link) so it would have reset BIOS settings as per that post/link. Also, once I update the BIOS settings (with new CMOS battery inserted) the settings should stay saved right?
This motherboard doesn't have any jumpers marked PSWD or RTCRST, so my options are limited to replacing the battery or resetting BIOS to default settings through the BIOS Setup option.
P.S.: I live in a remote area, and tech support isn't available hence trying out things myself
bradthetechnut
9 Technologist
•
9.6K Posts
•
40.6K Points
0
July 16th, 2026 22:04
If it's not saving date & time, and giving other problems, even with a good battery installed, CMOS may have become corrupted. The only way around that that I know of is to replace the motherboard. I'm sure they start off fairly cheap on eBay.
DELL-ChrisM2
Community Manager
•
1.6K Posts
•
7.2K Points
1
July 16th, 2026 23:08
* Open the online Vostro 3470 Service Manual PDF
* Do Ctrl F search
* Enter jumper
* That takes us to page 11 System board layout which shows #9 JMP1 =
Ramesh Iyer
2 Intern
•
47 Posts
•
83 Points
0
July 17th, 2026 02:43
@bradthetechnut Yes, I too worry about a failing motherboard, but there may be other reasons too hence sought inputs / feedback here. Will keep exploring possible options here and other tech support forums online. Replacing the motherboard would be the last option and the most expensive one too, so won't decide in haste.
Ramesh Iyer
2 Intern
•
47 Posts
•
83 Points
0
July 17th, 2026 02:48
@DELL-ChrisM2 Yes, I had noticed it on the motherboard but don't know what to do with the jumper as the user manual for this PC doesn't mention anything about this jumper in troubleshooting any BIOS related issue. You seem to be part of Dell so can you share any article on how one can fix BIOS related issues using this jumper? TIA
P.S.: I don't want to experiment on my own by removing the jumper, powering on, then powering off, replacing the jumper, and powering on, though that seems an obvious option
redxps630
11 Legend
•
16.2K Posts
•
82.5K Points
0
July 17th, 2026 12:50
There are three pairs of jumper pins typically labeled 12,34,56. The instructions are printed in a table on motherboard next to the pins.
https://www.ebay.com/itm/234688818759?
See pic
pins 56: clr CMOs
pins 34: clr password
pins 12: service mode
Dell standard CMOs reset is unplug power cord, move jumper to CLR CMOS x 5-10 sec then move back to password pins.
(edited)
bradthetechnut
9 Technologist
•
9.6K Posts
•
40.6K Points
0
July 17th, 2026 22:27
@redxps630 Are you sure that resets BIOS? Dell literature says move jumper, plug back in for 10 sec. Unplug and put jumper back.
By the way @Ramesh Iyer , if you do it that way, when plugging in PC with jumper moved, PC won't do anything visible.
(edited)
bradthetechnut
9 Technologist
•
9.6K Posts
•
40.6K Points
1
July 25th, 2026 23:48
@Ramesh Iyer Glad you got it working. :)