EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: PerranOak on November 04, 2019, 06:22:35 pm
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I have an old style MP3 player and am investigating it … well I was!
I wanted to see what current it took so I removed the AA battery and connected the player's terminals to the PSU. However, it would not start.
To cut a long story short, I tried "everything" including putting in a false battery in case, somehow (magic?), it can detect a battery, but nothing worked.
When I put a battery in - in the ordinary way - it works perfectly.
What could be going on?
Cheers.
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Some devices (Sony?) had a switch for battery type detection, primary or rechargeable.
Doubtful, but wire resistance could be a problem with external power, try decoupling close to MP3 player.
A couple of photos would help: Player and test setup.
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Probably too much inductance. Try adding a capacitor right at the battery terminals, 100uF or more.
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Cheers both.
While investigating, I forgot to set the current limit on the PSU - now I've fried it totally. I must have shorted something or something.
Thanks anyway.