Why its not charging and booting up

If your device don't charge for some hours and if you try to swich on with your charge connected and the red light still on.

Remove all the screws and the Rubber cover to found the battery wires, with care measure the voltaje of your battery, if that is less than 2 volts you need a new battery.

The first thing to order a new battery or build it by your self is check if the PCB board is working.

At this point you must disconnect your battery from the PCB board, connect the USB and measure if you got 7,5 Volts. If that measure is correct you can replace the battery an all will be work at the end.

You can buy a new battery at amazon, ebay or aliexpress but the most cheapest solution is build it by your self, I replace it for only 8 Euro.

If your PCB board don't have the correct voltaje at the output without any battery connected, I reccomend you buy a new deviene.

If you need some help with the battery build just contact me for more help.

If it’s been a long time since you used the device, there’s a chance that the device’s battery has dropped below the minimum voltage level considered safe for repeatedly discharging the device’s battery to. That’s usually between 3v and 3.2v. Many electronic devices that have rechargeable lithium batteries have a safety feature that prevents them from being recharged if they are over discharged. Honestly speaking, however, it’s not that it’s bad to use the battery if it’s been over discharged, but rather that they need to be recharged slowly and gently if they are that low. If you have a way to slowly recharge the battery back up to around the 3v level, then your device should charge them fine from that point on. I always make sure to keep some TP4056 lithium battery charge protection modules so I can recharge low batteries in such situations because they are really good at charging even batteries that are down below the 1v level slowly enough to not hurt them up to about 2.5v roughly, at which point they’ll start charging a bit faster until they reach the optimal charging point of 4.2v. They’re really handy modules and are really, really cheap. I picked up 40 for $10, so we’re about 25¢ each at that point. I think that as long as your batteries haven’t dipped into negative voltage levels, then they can be salvaged though they may take slight damage that would possibly shorten the life time but only by a few charge cycles. At several hundred charge cycles in, you wouldn’t even really notice the difference at that point unless you keep track of each time you charged them, which is unlikely. This all supposes that the charge state of your battery pack is indeed the problem, I could be wrong. If it’s not taking a charge, it’s either what I’ve said, or the lifespan of your batteries is up and they need replaced. Some brands add a mode for shipping a device, usually called “shipping mode” that limits any battery usage by the device to the bare minimum. If your device has such a mode, there might be a certain button sequence that when pressed will bring the device out of that mode, at which point you could charge it normally. Other times, a factory reset could clear any hiccups that might be preventing the device from charging. I had both of these situations happen more than once with Bose, but not yet with your device even though I also own the same one you have. Good luck, and if you need to find out how to do a reset or if the shipping mode thing applies, checking for a owner’s manual online is usually a good way to do that.