HDR just started randomly rebooting

Hi folks I wonder if you can help me :) Up till now my Humax HDR-1000s/1010s has been absolutely fine but over the past 3 weeks it's started randomly (crashing?) rebooting at the most inconvenient times. When it happens the screen goes black, I hear the HDD make a power-down whirr sound, then it reboots, occasionally it gets caught up in a boot-loop but mostly it comes back. This happens with live TV, or On-Demand, and most annoyingly while using 'Start from beginning' (when it's not yet available on iPlayer - it crashes and then we have have to wait for it to be released on OD).

I've tried tried the usual 'factory reset' but to no avail. I've even tried following various 'internet suggestions' like changing settings (power saving = normal, disable record buffer, etc), disconnecting the HDD and n/w cable, rebooting the router, etc. It already has the latest firmware (Feb 2018). I'm flat out of ideas so am guessing that this unit has gone faulty in some way (typically it's out of warranty - however I've reached out to Humax support but don't hold out a great deal of hope in getting a reply). I have also noticed a couple of other things with it too; a) it doesn't recognise the HDD - but I never record anyway, and b) it stopped automatically turning off when I turn the TV off - like it used to.

Does anyone have any more suggestions on how I can get my HDR to stop rebooting itself, or shall I just boot it into the bin.
Right well just to 'report back' I wasn't able to fix this issue myself. I contacted Humax Customer Support who sent me out a replacement box as the SATA controllor had seemingly gone faulty. £37/£47 for a 500GB/1000GB reconditioned device.