During the later half of the 20th century, batteries in children's toys have become more and more commonplace. For those of us who collect older or even vintage toys, this means that cleaning up batter acid leaks and having a process for restoring older toys that use batteries is essential. Here is my method for restoring such toys when they don't work after one battery change:
1: Replace the batteries
The batteries need to be brand new, fresh, out of the box batteries. Some toys, more specifically any toy that uses button cell batteries, need exactly the right amount of battery power to function. Additionally, the batteries that have been laying around the house for months may have lost the last range of their power needed to power the device.
2: Remove any and all corrosion from the toy. This is an easy process, but don't touch the substance with your bare hands. Corrosion can be blue or also a yellow dried powder.
Clean all metal pieces touching the batteries with isopropyl alcohol. sometimes you may even have to use a pipet to really get into all the nooks and crannies. (I didn't use a pipet one time and just poured some very carefully into my toy. Not the best method but it did work.) The metal can be corroded even if you can't see the corrosion, so i usually end up cleaning all of the metal parts touching the batteries even if they look clean.
3: What to do when steps 1 and 2 don't work
Open the toy, if possible, and look for any messed up wires or other deformities or things that look unusual. If you have one (I'm lucky that my dad has one, I do suggest borrowing one if possible), you can use a battery tester with two pen like pieces to make sure power is still circulating properly throughout the device.
Some stuff can be repaired, some stuff can't, and some stuff can be repaired if you have access to the right tools and know-how. Keep trying and don't give up until you have to!
I used this method to restore Julie's tape recorder and it had great success. I kept trying to use older button cell batteries that i had never used, but they had been sitting around for so long that putting all of them in there still wasn't enough power to power the device. A fresh pack of batteries straight from the store did the trick.
