JBL Flip 4 Won’t Turn On Unless Plugged In

JBL Flip 4 splashproof speaker, right side horizontal view.

When your JBL Flip 4 won’t turn on unless it is plugged in, this likely means one or more things. Either your speaker is broken beyond repair, the battery inside no longer recharges due to age or heavy use, or, you mistakenly put your speaker into service mode a.k.a. secret or weird mode. So, assuming that all the hardware and software is still okay in your speaker, we’ll cover here the last possibility. Thus, we describe below how to get your JBL Flip 4 out of service mode, and restore proper operation.

JBL Flip 4 Service Mode Details

First, when in this (often called ‘weird’ or ‘secret’) mode, the unit does not power ON unless you connect an external power source such as the included AC charger adapter. Thus, it will not run on the internal battery while in Service mode. Furthermore, when you do apply outside power, it powers up without you pressing the Power button. I.e. It comes on as soon as you apply power to the DC input port on the back of the speaker.

Further, you cannot turn off the Flip 4 while it is in Service mode, unless you disconnect the external power source. And then, it powers off without pressing the Power button. So when this service mode is active, the Power button appears to not work.

Indeed, none of the buttons seem to work in Service mode, except for the ones needed to exit service mode. E.g. The speaker won’t pair with any devices or other speakers when you press the Pairing button, and as mentioned, the Power button does not switch it off either.

How to Turn On Service Mode on the JBL Flip 4

This is what you may have done by accident at some point just prior to your speaker’s strange behavior starting… To turn on this Service mode, power up the speaker first, and then press the Connect+ and Volume UP buttons at the same time, until the unit powers OFF, which usually takes ten seconds or so.

Find these buttons pointed out in the next picture. Note that you can enter this mode as long as the speaker is ON, and it doesn’t matter whether it’s connected to external power or not.

Top view of the JBL Flip 4 speaker, with the -Volume UP- and -Connect- buttons highlighted.

JBL Flip 4 Won’t Turn On Unless Plugged In, How to Fix

Now you can restore proper speaker operation by disabling this mode. But note that when this Service mode is in effect, then to switch it back off, you must connect external power again. Why? Because when in Service mode, the JBL Flip 4 won’t come on without outside power. But you can’t change modes without powering up the unit first. Thus, you need the power adapter to make this fix.

So, connect your speaker to AC power and turn on the speaker.
Then, with the unit Power button glowing, you press and hold the Connect+ and Volume UP button combo for ten seconds or so, until the unit powers off.
Then, normal speaker operation returns.

Finally, at this point, the Power button should turn the JBL Flip 4 on again, whether or not you connect the AC adapter.