Member Avatar for rickfran

Tech support seems stumped. Power adaptor has green light when plugged into wall, goes out soon as connected to laptop. Motherboard and power adaptor both replaced, no change with battery in or not. Any suggestions..

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  • Latest Post Latest Post by micosmiling

Dani AI

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This pattern — adapter LED lit on the wall, then going out as soon as the barrel is plugged into the Inspiron — almost always means the adapter is entering protection because the laptop is presenting an overcurrent or short on the DC input. Replacing the adapter or even the whole motherboard will not fix the symptom if the short is at the jack, an SMD fuse, or an input MOSFET/regulator that is either shorted or miswired on the replacement board. suggestion to check the charger is reasonable, but simply using a higher-current brick rarely helps when a protection circuit trips. s observation about this appearing across similar Dells supports the idea that the DC-in area is a common failure point.

Useful checks and diagnostics:

  • Verify the adapter voltage unloaded with a multimeter (center pin = positive). If the adapter reads normally unloaded but falls to near zero when connected, the laptop side is shorting.
  • Measure resistance between the DC jack center and chassis ground on the laptop PCB (high resistance expected; near 0 = short).
  • Visually inspect and test the small ceramic fuse and nearby diodes/MOSFETs around the DC jack for continuity or visible damage.
  • With the battery removed and minimal components fitted, try powering with a current-limited bench supply or an inline lamp as a series limiter; watch for current spikes and heat (thermal camera or careful touch can reveal hot shorted parts).
  • Check that the replacement board is the exact part number for the model and that the DC jack is properly soldered and not shorting to the chassis.

Safety and next steps: working on the mains side and surface-mount power devices requires ESD precautions and some experience. If the short is not obvious (burnt part, blown SMD fuse), a professional with a current-limited supply and thermal tools will locate the failing component without risking more damage.

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Member Avatar for sittas87

HI Rick
please tell me that youve already changed the charger?? witch I doubt. Because it sounds like the charger

Member Avatar for rickfran

HI Rick
please tell me that youve already changed the charger?? witch I doubt. Because it sounds like the charger

charger and motherboard are brand new replaced by IT that's why the post, need suggestions

Member Avatar for sittas87

It sounds like the power thats supplied to the mobo isnt enough. try a charger that gives a higher output.

cheers
sittas

Member Avatar for joycee98

I know this sounds patently obvious, but have you tried the charger in more than one of your wall sockets? Just in case it is the wall socket at fault.

Member Avatar for micosmiling

Hi,
I have the Same problem on 6400....are your sure they put in a new mobo??? I've tried 2 Batteries,3 Ac adapter(small and large),Ac power socket on mobo.(wall Socket lol) All to no avail.
Can't get schematics for dell mobo unless someone knows of a place.
Will have to go for dell mobo about £170 on ebay out of warranty on my second mobo by 2 weeks.
All I can say is DELL you are S***e never again

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