DELL Inspiron 3477 AIO

[Sraros]

Hello,
I post this in this section for a Dell Inspiron 3477 All in one as the motherboard is more close to a laptop one.
So, the issue is that whatever adapter I use, I get this screen when it starts up. I tried aftermarket adapters and original HP adapters, both 65W and 90W. Minimum requirement is 65W.
I don't have its authentic Dell adapter as I took it for free in case I manage to repair it, but the HP ones I think are pretty much identical.

First thing I checked is if the dc jack on the board has an issue but with the MM I see all three pins, ground, 19.5V and center pin have continuity on the board.

Anybody have some idea?

[mon2]

Would you have a LA-**** number on the silkscreen of the logic board you can share? We can also study other schematics from Dell that will be similar to yours.

This is a DELL so the PS_ID signal that is mated with the center pin of the power adapter must exist. This is a single wire (1-wire) communication line that performs transfers of data to / from the EC controller on the logic board to the external adapter. Using this interface, the power adapter details are extracted -> if this line is defective or the details are missing, then the above message will be raised.

Trace this PS_ID signal onto the logic board and confirm that the same signal reaches the power adapter connector. Do not have the power adapter plugged into the AC socket during this test.

Then measure the voltage to ground using the adapter -> what is the voltage measurement?

Often there is a mosfet in the path between the EC controller and the power adapter connector that becomes defective. There are numerous threads on this website on this same repair.

[piernov]

Get a genuine Dell AC adapter of correct power rating…

AiO go in "Troubleshooting Desktop Motherboards, Graphics Cards, and PC Peripherals" as written in https://www.badcaps.net/forum/troubl...f-this-section

[mon2]

Sorry, missed this important detail -

I don't have its authentic Dell adapter as I took it for free in case I manage to repair it, but the HP ones I think are pretty much identical.

NO!! The original / official Dell adapters feature a 1-wire ID chip by Dallas Semiconductor / Maxim and is factory flashed with identification details of the power adapter. Without this information, the logic board cannot sense the power adapter's power rating. You can DIY add this ID but not worth the headache.

Hacking the Dell laptop power adapter | My Not-So-Boring Life (wordpress.com)


Dell Inspiron Doesn't Detect Charger - LFC#391 (youtube.com)
* if you have an official Dell adapter and still unable to detect the power adapter

[Sraros]

Thanks for the prompt reply.
Here's a photo of the logic board. I checked on the other side as well but there's nothing written.
I come back with the rest to check

[rogfanther]

First you need a Dell power adapter, not an HP one. Only the ones from Dell will be recognized correctly, HPs use another circuit to identify wattage, even if the connector seems the same.

[Sraros]

I will check with local sellers if I can test before I buy

[Sraros]

Hello again, eventually it was that simple indeed.
With the original charger the computer works just fine.
65W charger is enough. Thank you!