How Can a Mobile Charger Not Charge?

[#1]

I was a bit puzzled the other week when I went to charge an old SE phone. It lit up and showed charging. Hours later it was still charging. Except it didn't look like it was. If anything it looked like the battery had gone down a bit.

It's common enough to have a charging problem on a phone, especially old Nokias, but that's usually easily fixed with a wave of the soldering iron. This was a charger fault. It was putting out the volts but would I be right in assuming that it was somehow lacking the amps?

[#2]

Any chance of getting your hands on a  multimeter to check the  amperage ?

[#3]

No I never did, just checked the voltage. Tried two other SE phones with the same connector - same result.

In the end I found another similar same brand charger that I wasn't using with a different connector. Popped them both apart and soldered the connector on that one. And it then worked fine.

 I could see nothing obvious on the old charger board before I binned it but then I wouldn't know what to look for.

I'm just curious as I've never come across this before.

[#4]

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billnotben wrote:It was putting out the volts but would I be right in assuming that it was somehow lacking the amps?

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If it's putting out the volts, the phone will automatically take as many milliamps as it needs, unless the charger has an unusual fault.

More likely a problem with the battery itself, especially if it's a bit long in the tooth.

Li-ion batteries are especially prone to die if neglected for extended periods.

A meter measuring the current would have to be in series - not easy to accomplish.

Edit:  I see you've found the problem while I was typing.

[#5]

Yes this forum is a step back on the old one as it doesn't tell you that someone has made another post while you were typing.

[#6]

@billnotben.... Well, that`s called "upgrading".... just like Windows 10 !... it`s different from the old version, so it must be better, even if some features are no longer available....

Regarding the charging circuit.... maybe a diode had blown, or an electrolytic cap had shorted...

[#7]

Must be something invisible like that.

As you mentioned "forum" one other thing I miss. I expect it's already been noticed and mentioned.

In the old forum if you immediately did a quick edit your post never got a "this post was edited" type notice. Which seemed very sensible. This "improved" one doesn't do that as you can see.