Thanks guys. Couple of updates.
Robin - thanks so much for your PM. I thought I was doing the instructions from the QHY forum post linked above perfectly. I think I was doing it too literally, and when I was editing the inf file I literally copied the values that were on the forum post. Your PM "clicked" with me and I realised that I should have been using the hardware ID from my device, which is different to what's in the post.
So after doing that, I was able to get step 3 from here:
http://qhyccd.com/ccdbbs/index.php?t...16136#msg16136 to actually install successfully.
From there, I tried to follow the next steps using the vidpid.rar file. The device did not get detected as new and didn't get to do the install drivers mentioned in that word doc. Possibly because they were already installed by now? Anyway, I followed through with the second part which is running that ezmr.exe file and appears to flash the hardware with correct IDs? That seemed to work.
So I installed the latest QHY5 windows driver, the update, and the ASCOM driver from QHY website. All installed fine and now the camera appears to be working in Maxim DL.
So thanks so much all for your help there.
Now, as for the hardware modding. I'm not overly keen on that at this stage. What I might do is keep an eye on this issue. If it happens again, or regularly I'll reassess the situation. But in the meantime I'm hoping this is a once-in-a-blue-moon occurrence and won't need to do often.
If and when I do, I like Martin's idea of the post and jumpers. At least that's reversible etc.
Thanks again, all.