u/Lajt89

Hi,

I have an old Dell Latitude E5540 laptop. It works great after installing Linux and an SSD. However, I have one issue. Sometimes on boot, it shows an error like the one in the title.

Previously, it also turned on by itself once when I plugged in the AC adapter, and there was an error about the time and date. That was due to the CMOS battery, which I have since replaced, so that is no longer the issue.

When I push the AC adapter plug firmly into the port, the error never appears. I wonder whether the problem is with the AC adapter or the port. Is there a way to determine that? Unfortunately, I don't have another charger to test it.

Also, I don’t have a battery—the laptop only works when plugged into the charger.