The original power supply has a no load voltage of 12.56v.
Connect all the stats and it drops to 8.52v and 0.43a.
I got one of my spare thermostats and connected just the one to the original PSU. Voltage dropped to 10.97v and a current draw of 0.09a with the back light on, and 0.04a when it switched off.
I got time today to fit the new fuse, to my surprise the little LED that indicates the fuse is OK lit up, so those capacitors had held the power since the 9th March.
No load voltage is 12.52v, so very close to before, but with one stat connected it is now 12.12v, a lot better than before.
Now to go and pull the fridge out and refit it.
I seem to be collecting electronics repair jobs, our clock has stopped working - just corroded battery contacts, but my DS415+ Synology NAS has succumbed to the Intel Atom C2000 flaw, but I just need to solder a 100ohm resistor to the motherboard and hopefully that will fix it.
Oh, and another job I have is to replace many of the buttons on the thermostats as they sometimes don't work, I've had the buttons for years, just never got around to it.