SRS X-5 not charging and not switching off

[nalyr14]

My SRS X5 works perfectly when plugged in to AC power. The orange 'charge' indicator lights up when plugged in, as does the green 'I/O' indicator and the Audio In indicator. 

However as soon as I unplug it, it switches off. Also, I cannot seem to turn off the unit by pressing the I/O button; it just stays green all the time when plugged in. 

Any help would be appreciated. Thanks!

[cosmingpx8]

Check the power swplay

[nalyr14]

What do you mean by check the power supply? I can see the 'charge' orange light switch on and it also works when plugged in. Does this mean the power supply is working fine? 

Are there any other checks I can perform?