Member Avatar for kenearl

My friend's Dell laptop was working fine until one day for no apparent reason, it wouldn't power up. The power adapter seems to be OK, I measure 19.5 volts DC on the plug. When I hit the laptop's power switch, the green LED on the adapter just fades out and nothing whatsoever happens on the laptop itself.

This is a PIII which I installed Ubuntu on for my friend, and he let me use it for a month on a trip. I feel responsible for it not working, and want to try fixing it. The battery doesn't seem to hold a charge, so I had it plugged in most of the time. I suspect it's a bad jack for the power input, since the plug is vulnerable the way it sticks out, but why would it just suddenly go like this with no warning? Any ideas?

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Dani AI

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As and discussed, older Inspiron machines often fail to power because of problems in the DC-in path or board-level faults. A focused, safe sequence of checks will usually identify whether the adapter, the jack/solder joints, the battery circuitry, or a shorted component on the motherboard is at fault.

Recommended diagnostic checklist:

  1. Isolate power sources. Remove the drive bay/battery assembly as allowed by the model and try AC-only power.
  2. Verify the adapter with a multimeter off-load and, if possible, under light load or with a known-good replacement adapter. Confirm polarity and plug fit without relying on indicator LEDs alone.
  3. Visually inspect the DC jack area for movement, bent pins, broken plastic, or stress cracks where the jack mounts to the chassis. Check the board near the jack for cracked solder joints or damaged traces.
  4. Measure continuity from the jack center pin to the motherboard input fuse or filter components. A dead short to chassis ground or very low resistance suggests a shorted input device.
  5. Look for board-level failure signs: bulging/leaking capacitors, scorch marks, or lifted traces. A gentle wiggle test while powered (done safely and briefly) can reveal intermittent solder-joint failures.
  6. If the jack is PCB-mounted, consider replacing the jack or reflowing its solder pads. If the jack is part of a harness, inspect connectors and cables for broken wires.

Repair and recovery notes: PCB-mounted DC jacks on older laptops are common failure points and are often repairable by resoldering or swapping the jack assembly. If intermittent power returns, prioritize immediate data backup by removing the hard disk and reading it externally. Take ESD precautions and disconnect all power before opening the case.

If the fault is a shorted input MOSFET, blown fuse, or damaged power regulator, board-level repair or a replacement motherboard may be required. The thread posts correctly point toward the DC-in area; the steps above convert that suspicion into a methodical diagnosis.

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Member Avatar for coolraj003

Well you wont normally get warning for something like this, as it is quite old as well. Have you tried using different power supply cable to see if that makes it work.

It could be due to something getting shot on the system itself which results in the adapter circuit to fail and may be thats why the battery aint getting charged either. I would not push the laptop power switch on and off to check it unless i m sure the problem at the main power supply to the system is working just fine as it could lead to the mobo bing fried which will mean absolute death for the system. Look into the power connectors and leads to the battery and the socket where the mains are plugged in on the pc.

Raj

Member Avatar for kenearl

The laptop has a cracked case which I hadn't noticed before. After a week of trying, it finally just decided to power up. Possibly the planets were aligned just right, and I said and did the right thing at the right time but the owner is happy enough since he only uses it for playing music and videos once in a while, nothing important.

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