Awesome manual. Complete diagrams of all board assemblies as well as how to get to each part of the t.v. down to the individual screws and their locations. Get it.
This is exactly the service manual I needed.
Complete with all schematics, partslists, PCB layouts and alignment instructions.
This manual covers both the T-4970 en T-488F Onkyo tuner.
Text excerpt from page 42 (click to view)
T D A 8374 has a black current stabilization loop, that autom atically adjust the black level to the cut-off voltage of the picture tubes three gun cathodes. S ince no current is flow ing w hen the voltage the cathode is equal to the cut-off voltage of the tube, the loop stabilizes at a very sm all gun current. T his �black current� of the three guns is m easured internally and com pared w ith a reference current, to adjust the black level of R G B out. T he black level loop is active during 4 lines at the end of the vertical blanking. In the first line the leakage current is m easured (m ax. acceptable 100