Error 27 - Any Fix? Restore Question

Thanks for this but I've already tried all of it and it made no difference. The phone is not jailbroken (not sure if that's good or bad in this situation?). Apple Support are suggesting a restore but I'm trying to avoid it, or at least work out if I do it what the chances are of my photos, files, texts etc being available afterwards.

Today I will try iTunes on another machine to rule out a computer issue and will try a PC too but other than that, I'm out of ideas and worried that I'm going to lose the last three months worth of data. Frustrating because iCloud was set up but it never backed up for some unknown reason and the phone wouldn't allow stable access to photos from other software even though they were all on there (also frustrating because Apple never understood that issue either and the solution to back up to iCloud didn't work) but of course now I can't turn it on to even try accessing them from anything.

An update to this, when I tried iTunes on another Mac, I got a "device cannot be found" message but no error number. 😟

Thanks for the information, very helpful. I realised iTunes wasn't up to date on the other machine so I did that and tried to update. I got an error that it couldn't find the phone and when I tried a second time, I got error 27 so that looks to be the consistent issue. Is there any benefit of trying the update on a PC too?

I definitely know iCloud didn't do a full update because Apple couldn't see anything (only partial versions) when they looked, whether any apps have backed up, I'm not sure but it definitely won't include the photos as that was the main issue with the phone. Photos were saving to my photo stream (but only when the phone tried to restore photos in the photos and got nearly all the way through the process, which it hadn't done for a week) but will they remain there? My iPad that shows them is currently in airplane mode, should I do anything else? Obviously I can try to get the photos off it through my MacBook but I don't want to mess up what's there.

Now from trying various things online, my phone won't go into recovery mode. It's flashing between a white Apple logo screen, a blue screen (that can't be good!) and a black screen. Is there a way to get out of that?

I will take a look at recboot, thanks.

I'll try to back that up then, thanks. I can't get the Recovery screen back on the phone now, should I try reboot when it's like that? I hesitate to say it and tempt fate after today but I don't want to do anything to make the phone any worse!

The latest is I spoke to Apple support (before you had replied) and was able to get my phone back into Recovery mode. Was advised to try the update again but it didn't work and they have told me to try it again on a Windows machine which I can't do until tonight because it needs an update and iTunes to be installed on it. I'm not hopeful.

The phone was sitting on the white screen last night but had started flashing to a blue screen again. This morning it's black so I assume it's powered itself off.

They think it sounds like a hardware issue but interestingly said that if the Update won't work then a Recovery won't work either and the only option is to send it in for repair. Seems a bit strange to not even try to Recover it. I'm going to try the Windows machine and if it doesn't work I'll then try Recboot. After that, I'm not sure if I should attempt recovery? Surely I should just in case? At this stage, I'm not expecting to ever get it back working let alone recover any data and I'm not sure the cost of repair is worth the cost of the phone (which I was going to sell).