These A40s were in poor state when received and were ‘for parts/spares- not working’
They tested good with my multi meter and visually no magic smoke so I fixed the cases, re soldered a few joins and added music- so far so good for about 18 months. Delightful music was the result.
I recently began to note the right mono block was becoming increasingly sensitive to source equipment being turned on/off whereas the left remained silent.
Opening up the case I was horrified to see the glue from the previous owners attempt to secure transformer, caps and board to chassis had ingress to a few components and was turning black from its natural clear/brown state- I had obviously missed this when first received and now was very obvious.
I full afternoon of stripping components, cleaning, replacing and cleaning the board has resulted in a return to normal operation- no noise and I’ve noted the sound stage to be more “equal”.
Lesson learnt- check used equipment very very carefully and take note of small changes in their modus operandi as this could have progressed with severe outcomes.