Gene has some acid brushes headed his way. Lee gave me a great hint when I was doing my 700 with 99% isopropyl and a toothbrush. Use a acid brush snd shorten the bristles and they're stiffer, work great for cleaning off flux. Finish that other channel, order some new storage caps, and she'll sing at least for another couple decades. That's a good start on the amp and a enjoyable thread!
that is what i originally used...isopropyl and a tooth brush....did nothing...added acetone....again did nothing....i have already shortened the bristles on the toothbrush....only thing that would cut that stuff was scraping it off....came off in flakes...like dried scape...then i used the small brass brush...
i will send pics of the other board....its maybe a little worst....i dont know if that was factory scale or a repairman after the fact....
some places are better than others...
i can assure you...there are no missing traces...and no tin whiskers...and no cold solder joints....i retouched every stinkin one of them....
this board has wider traces that the 400....not much trouble with lifted pads...and was watching closely....even the old spotlight behind the board...
i will write fantasiaaudio....see if he can scrounge up some new caps...
thanks for the advice....ALL OF YOU!!!....i did more closely examine the caps....i dont directly see leakage...but, it is awfully trashy....and a new set certainly would not hurt anything....lol