The original motherboard in my IIcx experienced the most severe battery and capacitors leak I have seen at the time, worse than in case of Macintosh SE. It has been successfully fixed! After thorough cleaning with air compressor and IPA, I replaced the missing parts and fixed broken traces. Unfortunately the three 74xx ICs responsible for computer power on/off procedure could not be soldered to the same place and I had to add an extra board with DIP14 replacements.
Board before fixes:
Board during and after fixes:
Here is another board in a good condition. It has a socketed CPU and different HDD power socket.
Floppy Disk Drive
Sony MP-F75W-11G. The floppy was corroded from the motherboard battery leak and could not be fixed.
Here is another floppy in a better condition and its anatomy.
Hard Disk Drive
Quantum ProDrive P80S (product manual). HDD did not want to start properly – the discs were spinning, but the head arm was stuck and could not move. I needed to move it manually a lot of times, also with discs spinning before it slowly started to react and move. After some more time pushing it, it finally began to behave normally and drive was functioning normally.