I have had this AU-7900 for a while now, and the recondition is progressing.
The thing I was most concerned about was de-soldering the precious original output transistors to get some thermal compound underneath them. This went well, and to help alleviate the heat I used LMP silver solder to limit the heat as much as possible when re-soldering afterwards. I reassembled and tested it with no problems at all.
But disaster struck as I was manipulating the chassis of the amp, during re-capping the tone control board, I cracked one of the treble switch wafers :thumbsdn:
Anybody who has worked on one of these will know what a disaster this is, as there are tracks and resistors laid down on the switch wafer, for the multi-position switch to make contact with to alter the tone in steps. The switches seems to be unobtanium, except from a unit being parted out (rare) and they do not seem to be commonly used across the range.
A glimmer of hope
The part number seems to be 1090060 - and I can find this P/No at Sansui Parts Shop but it doesn't look like the ones I have in this unit - any information on this anybody? The ones in this unit have have 'open' wafers - the one at Sansui Parts Shop is a closed type - is it the same?
I have informed the owner who is understandably very concerned, and I can't tell you how annoyed with myself I am for making this dreadful mistake.
Any thoughts anyone?