Keyboard of Microsoft Sculpt Ergonomic Wireless Desktop Keyboard and Mouse stopped working

I doubt if Microsoft has released such an accessory. You might not find matching skin elsewhere too because of it’s unique shape.

Just take care not to spill water or most importantly, sticky stuff like tea or coffee. If it happens, it will be good to quickly use a hair dryer in moderate heat setting - the quicker you do it, the better it is (you can still try the same with the old keyboard).

Thanks to a tip found online, I have been using the glue side of sticky notes to clean the dust, hair & debris from flue spaces between keys occasionally.

Lastly, please treat the dongle like a VIP. You break it, you lose all. I have learnt my hard lesson purchasing Microsoft hardware.

A similar issue happened to me once with my previous set of Microsoft Sculpt Ergonomic bundle, when I accidentally spilled water into it. I ran a basic check with a keyboard checker and also by trying in a different PC. It was confirmed to be hardware damage. Being out of warranty, I opened it and could see broken links in the PCB track. I tested shorting with a duct tape and it worked great, but didn't try further to fix it permanently. In your case, if the basic troubleshooting fails, it might be a fault in a track (or group of tracks) common to all those non-working keys.

I invited trouble by buying another bundle only to see the dongle getting broken after a few months. I'm now left with the luxury of throwing 2 nice-looking keyboards & 2 mice into trash.