9510 not charging but works when plugged in

Unplug the system, remove the base cover and disconnect the main battery from the mainboard.  Hold the power button for 30 sec.  Reassemble the system and plug in the AC adapter, going into setup (F2 at powerup).  Locate the power adapter information and verify that the adapter shows with its power rating.  Does it, or does it show unknown?

Thanks - I just did that but couldn't find any info about the adaper in setup (by which I assume you mean BIOS/UEFI), and the issue isn't resolved when booting into Windows.

If the system is not sensing the AC power, try a new OEM Dell adapter first.

It is sensing the power in that the adapter is powering the laptop, and the battery symbol shows connected, and the white light on the front of the laptop shows it's connected. I guess the issue is more that the battery isn't communicating with the system/charger. The battery is nearly full, but whenever I unplug the charger it won't run on battery; it acts as if there is no battery attached (though, as shown in the screenshots, the battery monitor itself shows charge).

It also won't run via passthrough: again, the light comes on, but the system won't boot or remain on with a non-OEM power source, even though it's been working fine for the last year or so. (Last year I got the motherboard repaired after liquid damage.)

This story has shifted a number of times.  Simple yes or no:

1.  Does the system recognize the AC adapter's power rating.  Setup, F2.  Right on the main screen there will be an AC adapter notice.  Yes, or no?

2.  Is this a barrel connector (Dell power supply, OEM) yes, or no?

3.  Was the mainboard replaced or repaired?  Repairs can only fix evident issues;  collateral damage to a board from a liquid spill can take time to manifest.

If the power adapter is not OEM, the system may run (it's not clear it is running, based on the shifting story), but the battery will not charge.

I don't think anything has changed in my 'story'.

1. See the attached photo of my setup screen. It says battery is at 0 but charging, and 130W under 'Adapter'. In Windows, the battery graph says it's nearly full, the battery symbol says empty (but plugged in), and when I try to install firmware updates it says I need to plug in first. So the info the machine is giving me is inconsistent.

2. At the moment I am using the original OEM Dell charger, with the original USB-C connector. But for the past several months I've been using a USB-C cable running from my LG monitor to keep it charged, without any issues till a couple days ago. I only switched to the OEM charger because the monitor charging stopped working overnight. (I tried all 3 ports on the laptop.) I have a strong preference for returning to monitor charging.

3. The mainboard was repaired in April 2023. I emailed the repair guy today and he just made the usual point about Dells only working with OEM chargers. But I've used at least three non-OEM chargers without a problem. 

Probably not relevant, but I'm in a campervan with 24v power. I normally run my monitor using a DC-DC buck converter off Amazon, and have previously used it directly to charge the laptop. (https://www.amazon.co.uk/gp/product/B071SDW4QG) The voltage is within range, and I have a 10 amp fuse so it shouldn't get overloaded. I also assume there is some kind of voltage/current control in the monitor to deal with power delivery.

The day it broke I was charging the van batteries from mains power, which may or may not be a coincidence. There should be enough protections in place for it not to matter, but there would have been some change in voltage as it charged, so I guess it's possible there was some kind of surge. However, it was working fine before bed (powered via the monitor), and I turned it off at the wall overnight.

So the options seem to be:

(a) Something happened while using the machine that made it unable to run off power delivery (or charge using any charger) the next time I turned it on, without affecting usage during the current session.

(b) Something caused the problem overnight while it was disconnected from the power source (by switching the monitor off at the wall).

(c) Something happened when I turned the monitor (and therefore laptop power) on in the morning, but this did not affect the monitor.

All of those feel a bit odd to me.

(I am currently running it through the OEM charger plugged into a 230v pure sine wave inverter. I have also tried powering it through a Dell powered dock: it works the same as with an OEM charger, i.e. it will run but won't charge the battery.)

All of these additional details would have been better revealed up front, but it appears you have a recognized AC adapter, whatever supplies that.  And if neither a dock (thunderbolt) nor the OEM Dell charger will charge the battery, under ordinary circumstances, that would mean the battery is at fault.  However, given that the mainboard has been subject to accidental damage, the conclusion that the battery is at fault may not be 100% certain.  There's no telling what may have suffered either immediate or subsequent damage, possibly after whatever initial repair was performed.

It may be worth replacing the battery, but I suspect that won't solve the problem, and what probably should have been done before the repair was undertaken is what you need to do:  replace the system board.

There are multiple power rails in multiple layers of that board, any one or more of which could be the cause of the system not running on a fully charged battery.  This is the precise reason most shops either will not undertake a repair of a liquid damaged board, or will not warrant the repair for very long if they do.

The only guaranteed solution here is a replacement system board.

Im having the same issue.

They had replaced the logic board and gave new charger. it would charge battery then randomly stop showing the AC adaptor. then the battery dies and laptop shuts off.

then sent it out again and they replaced the AC adaptor. and its still happening.

I want a DELL manager to get incontact with me.