Hi, I've been going nuts over the same problem, still not found the answer. I've had cheap ebay dashcams and they've usually worked for a a year or so but have let me down.
I bought a Dod LS470w and the sd card Dod recommended. The camera gave alsorts of faults, the main one was not starting again after Park mode. The dealer asked me to do the h2testw, the card stopped after a few seconds and could not be tested. I tried a FakeFlash test that said the card was ok.
I put up with it for a little longer after formatting the card many times and trying other quality makes it seemed to run, then I tried to view the card at the end of December and although the red record light was always flashing... December was missing, only Novembers files were there.
I reported it and the dealer said it was a faulty card, I'd explained that I'd used other cards and all failed.
I tried to format the card and this time it would not format at all? The dealer was now convinced it was the card but I sent the lot back and got a everything brand new,
I tried running it for a week or so and it also failed, The dealer said he'd send me a much faster card and is sure it will work, fingers crossed. I'll try the new card and pray it works
While waiting I spare, new card, that has also failed... I've quick formatted it with 64-bit Windows 10, I've formatted it using command prompt, formatted it with the dashcam.... what do I have to do??
The Dod dealer is a nice guy but I'm fed up (being polite) I still believe I've been unlucky, and when working the LS470w is a fantastic bit of kit.
I've used several adaptors, card readers that take the micro sd without an adaptor, several card readers.
Please, if there is anyone out there who can help, both me and the dealer would be very grateful.