Quick disassembly and repair of a Zoom H6

A colleague got into audio recording during the early pandemic and used this cute little six channel recorder to grab some really interesting ambient sounds. Unfortunately the AA batteries failed and wreaked havoc on the internals.

Some Project Background

First step to see if this was revive-able was to inspect how bad the damage was. It was fairly clear there was a lot of damage from failed AA batteries, but it was not clear

The terminals were in such bad shape, the low profile ones were going to be really hard to replicate, so i opted to try and clean them up and then electroplate them. These were probably nickel plated so as long as I was able to get down to the base material it was possible that these could be revived. To get down to the base material I de soldered the part from the board and just ran it along some 1" wide 120 grit sand paper, while wearing a glove.

After a sanding and cleaning in an acetone wash, it was time to attempt to re-coat the remaining good contacts in nickel. This was going to be a challenge as while i tried to get most of the gunge out, there was still bits that were difficult to remove from the spring. Only the shallow profile springs survived, the longer thinner springs succumbed to corrosion.

It came out ok I think that I missed the key point that the battery springs are generally either nickel coated music wire or coated beryllium copper which would have been really bad to sand down the way I did. The coated music wire is the likely culprit, it's high carbon steel that is phosphate coated or nickel coated. It had to be a nickel coating as these are soldered to a board. I have no idea how the nickel coating would have been applied directly to steel without an internal layer of graphite or some intermediary. This is why the nickel plating stuck to small areas but not other areas, and also why the corrosion was so much of an issue, it was the high carbon steel generating all the rust.

Concluding Remarks:

• If Given that the H6 doesn't actually use anything but pack(+) and pack(-), i could have

• Charging from USB

• Testing

• Cleaning up the case