To confirm, the transplantation of UM8886BF onto HOT-433 v1 resulted in your onboard IDE controller not working, even when you force it to PIO-3 mode?

Exactly.

Are you going to put the UM8886AF back onto the motherboard?

Yes, I did, but the chipsets didn't survive re-soldering... Unfortunately, the elements are no longer available... You mentioned that you managed to buy a few UM8881/8886, I'll gladly buy one pair or maybe you'll be interested in something from my collection for exchange?

Sorry for the delay; I've been on holiday and won't be around for much of the summer. Can you confirm that you are still looking for a UM8886? If so, I can see what I have in my bin, but I'm pretty sure I only have the BF variant. You need AF?

Sorry for the delay too, I found and bought the entire motherboard. Thank you.