We have become aware of a common fault developing on ageing HDR-FOXes where the unit won't boot with the HDD connected but will boot without it. While this might seem to indicate a faulty HDD, in some instances it has been shown to be a deeper problem on the main board (not the PSU). The main diagnostic symptom is that the boot process continually restarts the moment "start system" (or the custom firmware announcement, if installed) disappears from the VFD (front-panel display), which is when the HDD gets powered up (but before it has had chance to be accessed). If the restart occurs later than this, it is more likely to be a HDD fault (see 3Bb). Diagnosis is confirmed if the problem remains when a different (known working) HDD is fitted, or the original HDD is shown to work in a different HDR-FOX (or when tested on a PC). Repair
might be effected by the relatively simple replacement of a capacitor on the main board. For more information see
https://hummy.tv/forum/threads/start-up-fails-when-hdd-connected.10164/.