My first TC died after 2 years took it in to apple they tried to power it up and told me it was dead and they ordered a replacement. I asked about getting the data of the TC was told that I should of done backups on 2 devices and I could not get the information of the dead TC as it could not be opened and if I open the TC it would not be replaced.
I had to wait a week for the replacement TC I found out online how to open up a TC and removed the hard drive and replaced it with a broken hard drive. The problem with the TC was on the power board of the TC which is located at the top of the I cant remember what the problem was. When I picked up the replacement TC apple looked at the old TC and did not notice that I had opened the TC.
The replacement TC has been working for the past 5 years only had one problem with the new TC it lost 6 months of backups I know they were there cos I had recovered files from it. When I spoke to apple about the missing backups and was told that I could not of done any backups.