Yeah, it's the battery that's problem. not even 2 year since i buy the m6 pro, although i rarely used it (couple hour a week, sometime not even touch it for weeks). And the technician also said, some small caps also crack because pressure from the battery.
My first Post on this site and thread.
I think I have the same battery problem and have contacted Shanling re the cost of an 'out of warranty' repair. No reply to date, likely down to the Lunar New Year Holiday.
My DAP is only the m6 21 not the pro or the ultra but was still a tidy sum of money for me and it isn't 2 years since purchase and like the member who has posted above Zeguym my player doesn't get heavily used and I generally listen to a whole album rather than random tracks or playlists. So usually it's played for an Album then turned off. I behave in the digital music world largely the way I always have from the legacy of a vinyl analog era. I'd spin an Album (one side) and maybe flip it and play the other.
My player began getting rather hot in the hand and the pocket. Thinking that may be contributing to the problem I started using bluetooth more (not my preferred technique) but not having the player in hand or pocket. It made NO difference, it still got hot. I also thought that it may be worse whilst using the 4.4mm balanced output but I'm not so sure that was the case. Really I've been clutching at straws and tilting at windmills to account for this thermal problem. Sure electrical devices get warm during use, batteries discharging and recharging get warm. But this was hot... not quite enough to cook on, but on the way there, noticeably HOT!
The final couple of days prior to cessation of life, other strange things occurred a) from a low charge state around 9% it took an eternity to charge with a 1.8A charger (I'm normally not that impatient and more kind to the battery and usually use a 1~1.2A charger) Perversely even after 15hrs @ 1.8A it still only indicated an 82% charge...so I called stumps on that venture. I tried using the player ( hardwired, single ended) and it played as normal but it was as if the battery was in free-fall without a 'chute very rapid decline in charge state....couldn't even complete a Candy Dulfer Album (love that gal!) And now it's as dead as a doornail... won't boot,no LEDs at all and won't take a charge. It's a Zero sum situation currently.
Something did occur to me though, albeit a little too late...When my m6 was purchased I also purchased the swish black leather case at the same time (I generally use as much protection I can get) and it also arrived with a front and rear clear protection shields (not sure of the material they're made of ) I attached both of those and the player has lived in the leather case since purchase it's completely unblemished,unmolested... But (there's always a but!) I do wonder whether the "Protection" is adding to the thermal woes of this device by actually insulating what would ordinarily be a fairly thermally efficient heatsink in it's metal casing. That's just a guess on my part.
I still have my baby mZero still going strong after about 4yrs (I think) still on it's original battery and no Droid OS to contend with. Can't actually fathom why Shanling doesn't go it alone with an OS as it does with the m0 and other players in their range. I have only one regret with this little device I should have purchased a set of baby fingers to operate it with from the outset, otherwise it's been a little gem. You could hide this device anywhere on your body or in your body (Yep even there!) wear it as earring if you're so disposed. For a A$100 initial outlay it's a cracker! Such a shame it's 7X the cost, big brother isn't/wasn't
I'll await to hear what the approximate cost of a factory replace/repair might be and if that's reasonable I'll go in that direction, but if it's over the top, I'll crack it open myself and install a replacement battery. If that doesn't work...it'll get a single swimming lesson, with hand on heart and in the background playing ... 'Eternal Father, Strong to Save" a Nautical Hymnn for those lost at sea!