this post was submitted on 19 Jun 2025
20 points (100.0% liked)

Ask Electronics

3707 readers
18 users here now

For questions about component-level electronic circuits, tools and equipment.

Rules

1: Be nice.

2: Be on-topic (eg: Electronic, not electrical).

3: No commercial stuff, buying, selling or valuations.

4: Be safe.


founded 2 years ago
MODERATORS
 

I tried to start my laptop earlier, only for nothing to happen. It won't start on battery or when plugged in (it can run without a battery when plugged in). The battery does seem to be dead, and so is the 3V CMOS battery.

I opened it up and noticed a circle visable on one of the inductors. Hopefully you can see it in the picture.

Could this be the problem, or is that normal?

you are viewing a single comment's thread
view the rest of the comments
[โ€“] [email protected] 3 points 1 day ago (2 children)

I am not exactly an expert at this but it could just be from heat. Do you have a multimeter to check if current can pass through it still?

Either way it seems like this shouldn't be affecting the laptop when plugged in because it is so close to the battery connector and it looks like the traces are related to the battery connector.

Do you get anything at all (battery/power LEDs) trying to run off of the battery? Is it possible that the charge port failed and the battery is just dead now? Maybe check the battery voltage to see how far drained it is.

[โ€“] [email protected] 1 points 1 day ago (1 children)

Current passes through it unfortunately, maybe it's possible there is a short between coils though. The inductor doesn't get hot or anything when plugged in.

  • I think I've managed to check the battery voltage, and it seems completely dead (mV).
  • I can measure 20v on the PCB whe n plugged in.
  • No fan, no LEDs, etc with either power source. There might be the slightest electrical squeek from somewhere, I will try and find out what ...

Even if I don't manage to fix it. Thanks for the suggestions ๐Ÿ‘

[โ€“] [email protected] 2 points 19 hours ago

When you saw that 20v on the board I assume that was right next to the charge port? There are often fuses that should be very close to that connector that you can check for continuity on. Usually marked with zeros because they act like a zero ohm resistor.

Even if the fuse is blown that might just be a sign that something further down the line failed but it would be an easy thing to check at least.