Logitech UE Megaboom based project

[kkrmkr]

Hi
Electronics is a field I know a significant amount of basics and I keep learning new things every day. I have a few UE Megabooms, first generation bluetooth speakers that were affected by salt water, corroding the charging boards only. Some, I managed to remedy partially, they would convey the power to the rest of PCBs but won't charge the battery. My idea is to integrate the PCBs in some second hand bookshelf speaker units, wire the amp section in bridge mode and power the system using an adaptor for power tools and appropriate DC-DC converter. Charging the batteries will be done externally, just like you charge a power tool battery. Once I have two of these I can get them to run in party mode and create a decent outdoor stereo speaker system. The challenge I am facing is the unit won't stay on if I just power the speaker using my bench PS. So I still need the original battery to operate it. I would like to operate it without the original battery, or even better without the charging board alltogether. Does anybody here have the experience here to guide me in the right direction? It would be helpful to understand if I am on the right track or not too. I'll post some photos and notes soon to give you an idea where I am in my attempt to figure out how to do that
here is the complete assy, 1 is the charging board where the battery is connected to, 2 is the main board with the amplifier, battery management and charging chip, a microcontroller chip and a ton of mosfets. number 3 is the bluetooth board with the on/off and pairing buttons, the bluetooth audio chip and the memory holding the software

the charging board I could only see mosfets or components linked to them, I guessed they were turning on the charging path and maybe converting the 5v to 11v for charging

on the other side of the board same stuff PS DC-DC booster


the main board has 2 or 3 PS ,I assumed for the amplifier, maybe the battery cahrging (wasn't sure why you'd need a second one when the charging board seems to have one already) a battery charging management chip and a microcontroller. There are a few voltage regulators as well. I am not 100% what the microcontroller's main function was. Is this the one that is likely to monitor the battery presence or through the battery module the information is passed onto the relevant chip (microcontroller?)


the last board is the bluetooth board containing the audio bluetooth chip and a memory chip with the software. Could this bluetooth chip operate the on/off commands? It si position very close to the on/off button

the battery board, I assumed has only duties to do with ballancing and protecting the battery from overheating or overloading

[kkrmkr]

Just to let those interested know that I managed to understand a bit of how all this works, or enough to remove the battery board and have it working with an 18V power tool battery without blowing blowing up anything