hopjohn
Silver Face
I'm not going to go through the whole triac install procedure again. If you want a good tutorial on that you can go view it in my KA-9100 thread posts #82 and #83. This is just to give an idea of how it can be done in the KR-4070 which has the infamously failure prone power / speaker selector switch.
To get the switch removed disconnect the large molex connector behind the switch. Then remove the metal rod that goes through the center of the switch and contact wafer by simply pulling it out the back. Then use a flat blade screwdriver or the like to open up the tabs on either side of the switch and remove the gray plastic switch housing. The two halves of the housing are just friction fit and pull apart to reveal the contacts inside.
My switch contacts were not all that badly pitted compared to others I've seen.
Once cleaned with some DeOxit D100L & G100L
In order to bridge the top and bottom contacts I soldered on the bottom leads first and routed them through the gap at the bottom. Then insert the switch housing back into the switch body and retighten the tabs.
The triac (thyristor) can be mounted conveniently atop the heatsink in the preexisting hole with a M3 self tapping screw.
To get the switch removed disconnect the large molex connector behind the switch. Then remove the metal rod that goes through the center of the switch and contact wafer by simply pulling it out the back. Then use a flat blade screwdriver or the like to open up the tabs on either side of the switch and remove the gray plastic switch housing. The two halves of the housing are just friction fit and pull apart to reveal the contacts inside.
My switch contacts were not all that badly pitted compared to others I've seen.
Once cleaned with some DeOxit D100L & G100L
In order to bridge the top and bottom contacts I soldered on the bottom leads first and routed them through the gap at the bottom. Then insert the switch housing back into the switch body and retighten the tabs.
The triac (thyristor) can be mounted conveniently atop the heatsink in the preexisting hole with a M3 self tapping screw.