Video MiniDisc repair - Sony MZ-EH50 Hi-MD Player - cleaning the internal battery terminal to get it working!
When you feel ready to shop for your first or next MiniDisc player/recorder, there are certain things to look out for... In this case, I saw a blue Sony MZ-EH50 - a nice, late-model (2005), affordable Hi-MD MiniDisc player that can play SP/MDLP/Hi-MD discs, but it only worked when connected to an external battery pack.
When you see units that work while plugged into a power adapter or an external battery pack, that's good news! That means it is working electronically, but perhaps the seller didn't have a gumstick battery to test with. It could also be that they tested with a gumstick and it didn't work.
It's relatively easy to fix devices like this and I've recorded a video showing you how to get to the more difficult, internal terminal. Normally, the terminal on the inside of the flip-open battery door is all you need to clean to get it working.
If you've tried that and it's still not working, try to get a light angled properly so you can see deeper inside the battery cavity and look for signs of corrosion on the internal (negative) terminal.
If you see it, we'll just need to clean it.
Don't be intimidated opening a player to clean the battery terminal. We're not going deep inside to replace a gear just yet... Typically just a few screws will get you inside.
Then, it's just a matter of cleaning the corrosion off with a weak acid like vinegar. Don't use too much! If you see that you're not making much headway, you can gently scrape off any big chunks and then get back to it with the vinegar. Some patience and finesse should yield a fairly clean battery terminal in just 5 minutes. After it's clean, use some alcohol (91% isopropyl is fine) to clean off the acid. As usual, don't use too much - we're not trying to soak it - but it will evaporate quickly so it's safe to use on electronics.
Typically, you can even test the machine before reassembling it!
I think I've already started a post about what to look for when shopping on Buyee - if not, I will! Seeing a model that I want that works on external power is always a good sign!