@Hlinsky
You are using original HDD (then 4.86 - original and works perfectly), or like pe1agp and itekweni - modified internal memory (CF or SD)? In that case - hardly old 4.86 would carry modern cards.
@pe1agp
you are using finally SD card, whilst itekweni - CF. Maybe there transformation from 910 to 710 is hidden? As you already know - after I replaced CF-type HDD in my GO700 with CF-to-SD adapter - nothing changed in ttgo.bif report - perhaps due to CF interface of adapter...
PS and of course - first I updated bootloader, as very doubt old original one would see modern SDHC inside adapter (maybe I'm wrong and it really would - but don't feel to disassemble device too often)...