5400 need to reset rtc every time, cannot update bios

Question

I have a latitude 5400 that will not turn on unless I follow the procedure to do the RTC reset by holding the power button for 20 seconds while device powered off.

Specifically I push the power button and sometimes the fan will kick on more often it will not, the keyboard will light up, the power button will light up, the screen will not light up, and it will sit in that state indefinitely, until I hit the power button in which case you can hear the fan kick to full speed and then the machine turns off. So I will hold the power button until I see the two white flashes at the front in which it does whatever it does and then it boots to the Dell logo screen

This will let me hit f12 to open the one time boot menu screen, or f10 for bios

Every single time I complains about the date and time not being set, assumably because of the rtc reset.

F1 from this error screen continues to the one time boot (as long as I tapped f12 at Dell logo)

The hard drive has an issue, the problem persists with the hard drive disconnected

Entering the bios setup is possible but none of the settings will persist to the next boot in which I have to rtc reset. I can add UEFI entries, they do not persist

If I try to update bios from the f12 screen, it will show me a window that lets me choose a file, I've tried the 1.5.1 and the 1.12.1 files, the laptop will go to reboot to install the firmware but instead of black screen appears and it starts having an LED diagnostic code of two orange three white, which I think is can't find ram

That diagnostic code will continue to flash until I do the RTC reset again. This happens every single time I try to do the BIOS update.

I cannot get the laptop to boot into BIOS recovery (I somehow was able to get the BIOS file not found LED flashing code at one point but I could not get that to appear again)

Running the machine diagnostics from the one-time boot menu indicates that everything is fine except for the hard drive which just doesn't seem to be able to finish the test with no real error or indication as to why. I have not yet tried a new hard drive as the problem still exists without a hard drive connection.

I've tried to install an OS, such as Windows or Linux, but so far, every time the computer reboots I have to do the RTC reset and every time I do the RTC reset it doesn't have any uefi-enabled boot partitions listed. It won't save any bios settings that I try to set, and it flashes the two three error code when trying to use the internal flashing mechanism.

I think it was improperly provisioned; I received it second hand with no information of the previous owner. Service tag

JushiJester · Accepted Answer

I've been building and repairing computers as a hobby since 2004; I had tried a new battery, I had tried different RAM modules, I mentioned in my post that the blink code was referencing a ram module but it was a strange error considering it only happened when I tried to update the BIOS. Immediately after trying to update the BIOS would be the diagnostic code for the ram.

The culprit is this poorly placed strip of material, it was placed over the event holes right over the ram modules; removing it allowed my BIOS to update and now I have no problems.

JOcean · Answer

On a machine that is relatively new it is hard to believe that the CMOS battery is bad but all of your symptoms point in that direction. Have you tried a new battery for the CMOS yet? Instructions are here. And for your own safety and security please do not post the service tag number in the forum.

U2CAMEB4ME · Answer

Welcome to the Dell Community @JushiJester

I think we may be dealing with another BIOS engineering defect.

https://www.dell.com/community/Latitude/Latitudes-randomly-switching-from-AHCI-NVMe-to-RAID/m-p/8056269#M37001

https://www.dell.com/community/Latitude/Dell-Latitude-5420/td-p/7958877

I am not sure what you should do next.

@JOcean

What do you think???

From experience I suspect another BIOS engineering defect.

Best regards,

U2

JOcean · Answer

I have seen this on a web page and seems to confirm that something is going on. Your links lend some credence to the fact that a very unusual problem is occurring. But far be it from me to start pointing fingers at an engineering defect. And though I suggested a CMOS battery, this system came out of warranty 10 months ago and unless there were a bad batch of batteries it is hard to believe. I would change the battery anyway just to rule out that component as the cause. But if it is a BIOS problem then Dell tech support should be involved as they may have additional information about this Latitude series.

Also a bit of input from @speedstep or @jphughan or @RoHe would help as well. I have personally never seen a BIOS with that type of problem unless it were the battery but they may have more expertise when it comes to BIOS problems such as the OP has stated.

RoHe · Answer

@JushiJester -

I'd start by replacing the motherboard battery as @JOcean said. if nothing else, you rule the battery out. Looks like it's a CR2032 with leads. These batteries cost ~$8.00 but make sure you get one with the right connector. Some have of them have a 2- and some have a 3-pin connector plug. NOTE: The Latitude 5400 and E5400 are different and don't use the same coin cell battery connector...

Does this problem occur when PC is connected to its power adapter and the adapter is plugged into a working outlet? Or only when it's not connected to its power adapter?

Is PC powered off and connected to its power adapter when you do the RTC reset?

What color is is the battery status light? Does it correctly indicate when PC is charging?

You mentioned a 2,3 blink code. The Service Manual says that means "No memory or RAM (Random-Access Memory) detected". Does RAM need to be re-seated in the slot(s)?

You also mentioned getting this PC 2nd hand. So there's no way to know if the previous owner abused, dropped, spilled something on it, or otherwise damaged this PC before you got it...

And you can always contact Dell's Out-Of-Warranty Repair to get an estimate for a factory repair, at your cost since it's out of warranty.

EDIT: And it's also possible the CR2032 battery connector cable is just unplugged from the motherboard, so that's something for you to check out...

JushiJester · Answer

The problem was not a failed component, but the improper placement of thermal transfer tape. Thank you to everyone who responded

U2CAMEB4ME · Answer

@JushiJester  Great to hear you solved the problem. Glad to hear we do not need to add this one to the list. Regards, U2

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5400 need to reset rtc every time, cannot update bios

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