Accidentally connected 2 amps together, fuse blown. Sony STR-DN1080

Hi all, hopefully I've found the right place to get some advice. I have a somewhat complicated home cinema set up using what I (thought) was a passive switch which switches a set of speakers between my desk stereo amplifier and my home cinema amplifier as the rear/surround outputs. This only works due to the layout of the room being favourable!

Speakers ----> Switch < Amp1 (SMSL) /Amp2 (Sony)

Switch is this one:
Nedis Analogue Audio Switch Manual with 3x (2x RCA Female) - 2x RCA Female, Black: Amazon.co.uk: Electronics & Photo

This has been working flawlessly for months, whenever I use the home cinema I flip the switch and the speakers run from the Sony amplifier instead. But yesterday I'm not sure if the switch malfunctioned or what, but the fuse has blown on the Sony amplifier and I suspect some leakage occurred sending the full power from the desk amp into the back of the Sony amplifier. Now when I try and turn it on, it clicks repeatedly and the green power light comes on and off every second or so.

I am no electrical engineer but I opened it up to take a look and noticed that there was a clearly blown glass fuse (T3.15AL250V) and a very faint burning smell. I realise I could just order a new fuse off Amazon and try it, but I suspect that may cause further damage if there are other problems. What is likely to be the issue here before I start a make the quite long journey to the repair shop I'd rather be armed with some knowledge.

Thanks,
Alex
 
That is a line level switcher not a speaker switcher, the difference is the voltage level the switch is designed to handle, that may have been a contributing factor in why it failed.
This is the correct type of device to use... Speaker swithcer Notice it has binding posts not RCA connectors.
The other thing you likely have to address is the blown fuse in the Sony, this usually happens after something in the amplifier output stage dies so there is a very good chance it will need a visit to a repair shop. If you replace the fuse and it immediately blows again even with nothing connected this is confirmed.
 
You're right, that would have been better. On closer inspection I think the reason may have been that I shorted the positive / negative on one of my cables which caused the connection between the 2 amplifiers inside the switch via the ground. Expensive mistake to say the least!

Would it be safe to try and replace the resistor or am I best taking it straight to a repair shop?
 
To update on this. Got it fixed at integrated services in Kettering who were absolutely top class and very professional. The repair in the end cost be £77 + £15 diagnostic fee including parts and labour. The issue was as expected with the output stage for the rear channels which blew the fuse. They had to replace a number of transistors and other parts on the board but got it sorted and it works flawlessly. I travelled a bit further to get it to these guys simply because they seemed to know what they were talking about over the phone and answered very quickly.