VD1212 replaced with 2x 1N4148 in series is standard procedure, nothing particularly weird about that.
To solve that kind of problems (eg noise when warm up) i use freezing spray. when the problem starts, spray each transistor separately and detect the defective one in minuts. Never failed.
Roger, thanks, the KSA992 is bonded together with heatsink grease on the flat parts of the case and then zip tied together. The emitters are then soldered together.
el156, yea that was also recommended but I didn't have freeze spray at the time. This is my first restoration and decided to go all out and make it all new. $6 for 100 new KSA992... not bad. The biggest cost was the replacement for the 50V 15000uF pair of capacitors. The size was 51x80mm, the closest match was 50x80 50V 22000uf and $25 each. The old ones are still good but had a lot of use.
el156, yea that was also recommended but I didn't have freeze spray at the time. This is my first restoration and decided to go all out and make it all new. $6 for 100 new KSA992... not bad. The biggest cost was the replacement for the 50V 15000uF pair of capacitors. The size was 51x80mm, the closest match was 50x80 50V 22000uf and $25 each. The old ones are still good but had a lot of use.
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