So just to bring this thread to a happy ending I am pleased to confirm the A77 is now back to life and fully functioning - well 99%
My initial inspection of the snubber networks and the vulnerable Capacitors C113, C114 and C115 was not very thorough (blame the bad light and my eyes !).
In fact the 4.7Ohm resistor on the Right Reel motor had fried and C113 was badly cracked and damaged at the rear and leaking goo.
C113 had 13.8ohms DC resistance - so this was not good for the reel motor windings, hence burning and broken wires.
I've replaced all snubber network components, plus new Motor Caps.
The replacement motor seems fine
Only minor issue I have is braking on small diameter reels. Strangely 10inch reels appears ok. Have cleaned brake linings etc and adjusted tension (trial and error as no tension measurement available).
I mostly use the 10inch reels now so not a big issue.
Thanks to all for the posted comments. It's good to solve a problem like this and see an old bit of kit come back to life.'
