The disk drives (see the other thread) are $28. The Disk Drives work also on any amiga. I have disk drives with faceplates too if interested. These are only $22.
Will see if i can get some info about A4000T. Meanwhile, your low low cost is getting the missing part from local electronics repair shop. They can do the job for you i bet for low cost. Soldering that is like 30 seconds.
ANY other symptons you had on your Amiga 4000T ? did it boot at all? or just went on & off?
Don't forget ALICE chip gets really hot so you need low profile heatsink for it - drop me an email if you don't have one.