One for the old timers on the list :-)

My Cambridge A75 power amp has a dodgy left hand channel.

I have two choices:

1. Get it repaired - I'd like to do this because, when it was working
I was very happy with it, however I've no idea where to take it :-( No
one at Cambridge Audio was old enough to even remember this amp so
I've got no circuit diagram....

2. Get a different, new-to-me, power amp to compliment my C75 pre-amp
(which I'd like to still use because a) I'm poor b) it has an MC input
for my deck/cartridge).

So, any advice? :-) Option 1. where do I take or send it to be worked
on or Option 2. recommended complimentary amp?

Cheers

Steve