Buffalo Linkstation Quad on the blink...

[szimbler]

Hi there, I have an old Linkstation Quad LS-Q4/R5 plaing up. I have rebooted a few times now, and each time it goes into a disc check cycle - NasNavi is currently saying "Status:
I21: Checking drive 1... (2017/01/13 09:18:51)". The front light is also shashing th I21 message. It's visible on the n/w but the web interface says "Warning Back Fan malfunction" though the fan is running and sounds OK. So which do I believe? The web interface also says "An error in a RAID Array has been detected. Select restructuring disk and click `Restructuring RAID Array`" but this will apparently erase the data in the 'replacement disc', and I haven't replaced any discs, so I'm worried this may wipe everything.

On the disc check page it doesn't allow me to select any discs for checking, perhaps because it is already checking? Who knows...

It's loaded with 4 x 1TB drives set up as RAID 5, and I have a spare disk ready to go.

I'm not sure what to do next. I'd rather not lose all the data, as this will wast a whole load of time and I'll lose some non-essential data.

I'm happy to reboot a few times, and wait a couple of days to see if this I21 status changes, but I have done this a couple of times, and it didn;t end well. Last time it just ended up with a flashing orange light (continuous short flashes that didn't correspond to any error/info code I could find).

I'd be very grateful if anyone can suggest a protocol for identifying the problem (as the LS itself seems unable to do so) and restoring functionality, ideally without losing data.

All polite suggestions accepted with huge thanks.

[szimbler]

one day on, and NAsNavi is still saying the same thing...
Status: I21: Checking drive 1... (2017/01/13 09:18:51)
whilest the webUI is still saying Back Fan malfunction on the home page, and on the disk managment page it's showing no RAIDS configured...

Can anyone make any suggestions...at all?