A quick fix.
I gave my wife a TEAC MP390 mp3 player for Christmas several years ago. She dug it out recently because she wanted to use it while out walking.
Sadly, the MP390 would no longer hold a charge. A full night on the charger was just enough to get it to turn on then immediately shut down.
I opened it up, and found this:
The lithium-ion pouch cell it uses is poofed up - definitely gone bad.
A quick look around Amazon turned up several pouch cells of about the right size and capacity - and at a price that made fixing the MP390 look more reasonable than replacing it.
Here’s the new battery, just about ready to be installed:
The capacity is a little lower (320mAh rather than the 400mAh of the original) and it is shaped slightly different, but it’ll fit in the MP390, no problem.
You’ll notice that I have clipped one wire there in the picture. That is on purpose. The battery wires have to be soldered to the circuit board. To prevent accidental short circuits while I was working, I only ever had one wire clipped, stripped, and loose at a time.
Soldering the wires still meant being danged careful - the pads on the board are so close together that a minor slip of the soldering iron could short the battery terminals. You do not want to short a lithium-ion cell.
|New battery connected|
Before I put it back together, I turned the MP390 on and made sure it was happy with its new battery.
The battery is showing a little bit low, but it hasn’t been charged yet. The display is all lit up and music plays. Time to put it back together.
Still working after stuffing its guts back in its box.
I’ve got the old cell in a box of stuff to be recycled - with the wires clipped to prevent short circuits. Even a supposedly dead battery can surprise you sometimes. It might not deliver current for very long, but it might deliver enough to make things exciting for a few seconds.
The MP390 was built before people went in whole hog on “smaller is better.” It is small enough to take anywhere, big enough to use with normal fingers, and big enough that it is screwed together instead of glued together.
Anyway, the MP390 is running again.