Thanks for the update.
Since this thread started I have bought a 2nd Dell (complete with genuine Dell charger). In the F12 diagnostics it correctly identifies its 65w adapter and my previous Dell 90w adapter. Interestingly it consistently identifies my universal charger as a 90w adapter (still don't know how it does that). The erroneous HP adapter supplied with my 1st Dell is still identified as 'Unknown' and will power but not charge the laptop.
there was this old thread from the Dell forums about a similar problem
Thanks erpster4,
Yes, I have read most, if not all, of the old threads. There seem to be a dozen or more possible solutions but none that is guaranteed to work under all circumstances. At the moment my battery is showing 100% charge at the battery icon. When I go into F2, the battery information shows AC Adapter Unknown (a Dell Adapter) and battery health normal on 99% Charge.
When I go into F12, Diagnostics, it shows AC Adapter as 1 Watt (the actual adapter is 130 Watt).
As I have been running the laptop with the adapter plugged in for a number of days now I have just unplugged it and will see what happens when I plug back in with the battery having partly discharged. The one suggested solution I have not attempted is to update the BIOS as doing this can, I read, cause more problems than it solves. By the way, all the Dell diagnostic tests I run show everything in the best of health. Clearly the diagnostic tests themselves need a diagnostic test.
This has been seen by others. There is a fault somewhere, in the adapter itself, on the motherboard, or in the DC in socket/cable. Some examples of others seeing '1W' adapters:
Latitude E6540 - "Plugged in not charging" - Dell Community
M4700 Not recognising AC Adaptor correctly - Dell Community
Is the temperature of the adapter too high?
- Unplug it from the mains then immediately hold it tightly as if it was your last £10 note.
- If you cannot hold it comfortably because of its temperature then replace the adapter.
Personally, I think the contrary indications you have in the bios & in its behaviour show that it should be replaced anyway.
- Whatever the actual fault is, you have an intermittent fault that almost certainly involves intermittently poor connectivity [hence my guess about the temperature].
- Intermittent connections generate unexpected & excessive voltages at the point of connection that might be causing physical damage to your computer.
- You can really only find out of it is the adapter or the bios causing the 1w reading by replacing the adapter or the computer. The adapter is cheaper.
Best of luck,
Denis
Denis, I tend to agree that intermittently poor connnectivity does seem the most likely cause. However, the adapter runs warm but by no means hot. Yesterday, just to see if anything had changed, I ran the laptop for some time with the adapter disconnected. The battery discharged,of course, down to 76%. Upon reconnecting the adapter the "Plugged in - not charging" message re-appeared.
I am becoming more and more tempted to try a BIOS update to see if it has any effect. The present BIOS, A14, dates from 2013. Dell show a couple of updates, one in 2014 and another in 2018. I may, however, be able to borrow another AC adapter just to see how that works.
Gordon,
I avoided referring to bios updates purely because your symptoms are variable.
- If the cause of the problem was the bios then I'd expect the 1w reporting problem to be permanent
- furthermore, if it was a bios problem then I'd expect the problem to have started when you ran a Windows version update.
Having said that, there is no need to be afraid of bios updates and they are worthwhile in their own right. Just make sure you have ac power connected so the computer stays on the whole time. I have had bios updates on all my Dells and they have always run correctly.
Denis
A further update on "Plugged in not charging" (PI,NC). A few days ago I deliberately discharged the laptop battery and on plugging the charger back in the battery was not charging. This time, because I had read the suggestion somewhere, I just disabled the Microsoft AC Adapter and the Microsoft ACPI-Compliant Control Method Battery in Device Manager. I then enabled them and found the battery was now charging.
Today, as a further test, I again let the battery discharge, down to 6%. When I switch the charger back on I found the battery icon displaying the "PI,NC" message when I hovered the cursor over it. I went into Device manager and disabled both the Adapter and the ACPI. Immediately a message appeared on the screen to the effect that hardware changes had been detected and the laptop would restart, which it did. The battery icon had disappeared, as expected, but the battery charging light was on. I went into Device Manager and both Adapter and ACPI were still both showing Disabled-Code 22. The battery charging light was still on however. I enabled both Adapter and ACPI and the battery icon re-appeared, again as expected. The battery was now showing 11% charge, so I conclude, though I do not understand how, that the battery was still charging in spite of having both Adapter and ACPI disabled. As I write I have now disabled the Adapter only in Device Manager but the battery is still charging. I have now enabled the Adapter and disabled the ACPI. As the battery icon has gone off screen I will wait a few minutes before I enable it and check the degree of battery charge. The battery charging light is still on I should add.
Having now enabled the ACPI I have found the amount of charge on the battery has increased quite a bit.
It seems to me that, as far as my second hand Dell E5420 Latitude laptop is concerned, it is necessary to disable the Adapter and/or ACPI in Device Manager to kick the battery charging process into action. I really would like to know why this is and, more importantly, what purpose the Adapter and ACPI in Device Manager serve other than to display the battery icon and start the charging process when disabled.
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