576/Repairs: Difference between revisions
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RESULT: -75V drifts badly as the machine is turned on and heats up (High @ -73.5V when turned on and drifting slowly to -75.05V when warmed up.). | RESULT: -75V drifts badly as the machine is turned on and heats up (High @ -73.5V when turned on and drifting slowly to -75.05V when warmed up.). | ||
Found shorted D83 - 1N4152 not aware of symptoms related to this defect. | Found shorted D83 - 1N4152 not aware of symptoms related to this defect. This would have affected the DAC Function. See Page 3-9 for Circuit Description. | ||
Replaced D708 with proper 9V TC ZENER, -75V Supply is now rock solid @-75.015V, no "drift" as the machine is turned on and as it heats up. | Replaced D708 with proper 9V TC ZENER, -75V Supply is now rock solid @-75.015V, no "drift" as the machine is turned on and as it heats up. | ||