I have a Monster Superstar Backfloat Bluetooth speaker just over a year only used a couple of times now it will not charge.....any ideas??

Page 7 of user manual
SUPER STAR 3900 OWNER'S MANUAL Pdf Download ' ManualsLib
says if you are using external speaker, internal speaker will not work. Try using external speaker. If sound does not comes out then problem is with audio section. If yes then check the external speaker jack.
Schematic Circuit Diagram is here
SUPERSTAR 3900 Service Manual download, schematics, eeprom, repair info for electronics experts (elektrotanya.com)

Amplifier failure

Hello Teresita, have you tried if you do this when it is connected to the charger? If not, it is possible that it is the battery
It may be that the battery of your Monster, can be low and that's why it gives you 20-minute operating cycles
Discuss what happens when you use it with the charger
Greetings Franco Dosil

Hola Teresita, has probado si hace esto mismo cuando esta conectado al cargador?, sino lo hace es factible que sea la bateria
Puede ser que la bateria de tu Monster, puede estar baja y por eso te da ciclos de funcionamiento de 20 minutos
Comenta que sucede cuando lo utilizas con el cargador
Saludos Franco Dosil
https://data2.manualslib.com/pdf6/132/13189/1318808-monster/superstar.pdf?31ea676de5424f0ba0c6f2998e00a6ea&take=binary

solder in a new battery.

Not charging is one of two things. The battery is bad or the charger is bad. It is easy to check the charger output with a meter to determine if that is it.

Problem connecting Windows 8.1 pc to JBL Charge bluetooth speaker ...

answers.microsoft.com/.../windows/.../windows8...connecting-windows...

When I try to connect the pc through Bluetooth to the above wireless speaker ... 2) What is the model of the JBL Charge Bluetooth speaker? ..... I am already able to play music from my iPhone 5 on this speaker via Bluetooth with no problems.

Cannot connect JBL Charge Bluetooth - Networking, Internet ...

en.community.dell.com/support.../network...wireless/f/.../t/19525571

Dell
Sep 22, 2013 - 16 posts - ‎11 authors
23 Replies; 16 Subscribers; Postedover 2 years ago ... I'm trying to connect my JBL Charge Speaker bluetooth with my Dell Studio 15 laptop to listen .... I am having the same problem, did you find a fix for this? ... not support audio output, then you need to add a Bluetooth adapter which includes a CD driver.

JBL Charge 2 ' Portable Bluetooth Speaker with USB Charger

www.jbl.com > Wireless > Portable Bluetooth Speakers

JBL
Rating: 4.3 - ‎110 reviews
Most popular JBL Charge 2 wireless portable speaker can charge any devices via USB... You can easily connect Charge 2 to any Bluetooth-enabled device by giving the portable's ..... Charge with proper charger or a USB port form computer.

Mine wouldn't either. Now I have paired it with the Bluetooth and it installed something (drivers?), and now it works. So, now how do I know if it is always connecting Bluetooth or wired? I connected the wire and it is still working, so now how do know if I really need the wire or not???

check if left speaker is shut off /connections one speaker my be on a side the other on b side check all speaker connections

change the battery