OK, have reformatted the card, copied music files back onto the card and it's working again, at the moment.  When formatting I used guiformat but this time I clicked on the 65536 in the volume drop down menu.  Not sure what difference it makes...  Anyway for the purposes of anyone else...

Thanks for suggestion, tried it and unfortunately it didn't work. All files read via the computer as well.  I am now copying the card to computer and then I'm going to try reformatting the card, see if that works.  

Hi, I have 2 64gb sandisk cards my ak100 has stopped reading one of the slots and bizzarely it can vary.. Library keeps scanning but no luck. The cards aren't full and there's 2.5 gb spare in the internal drive. Can anyone help? Thanks

I found exactly the same with the ak100, EQ flat is the most neutral.

Hi, I too had a problem with the method you are using until I remembered reading that the software wasn't compatible with win 7 64bit.  So I installed the iriver plus 4 software (it's the one in the root menu) into the 'program file' but not the 'program file(x86)', opened it and the...

Could be a glitch in the firmware. Have you tried reinstalling most recent firmware - 2.20?

Hi, I have just purchased both the ak100 and beyerdynamic dt1350. Had them for 2 days only. First impressions are that mp3's can sound a bit thin but Wav/aiff sound much more involving and dynamic - fuller sounding and more natural. I'm coming from a cowon d2 and audio technica es55 rig and the...

Hi guys, I have been trying to add album art tags to AIFF files via iriver plus 4 and another id tagging software (I think its called 'tagrename'), to my ak100 but not having much luck. Anyone had any successes with this? Really enjoying this player. Thanks.

Hi, I borrowed an ak120 and played hi-res and standard flacs through my car stereo ( vw dynaudio) and it sounded really impressive. Lead is a white one made by Chord, I think it was about £40.

Sorry to hear about your AK120. Did you check whether or not the Post Office have CCTV?