rcaman
cornbread george
I bought a non working cr-2020 upon inspection someone had made an attempt at repairing the power supply
and made a mess. after a complete power supply recap and a correct relay and the Yamaha modifications resistor upgrade no relay click at power up. measuring the +25 volts was good but the -25 volt line was being pulled down to -2 volts. short on the -25 volt line was traced down to tr753 or tr754 i forget which one they are on the pre mod. e board i replaced both and she fired up and went to singing.as for the panel lights the Yamaha engineers should have been fired on this receiver. Pitiful to say the least i removed the green filters on the watt meters and tuning pointer use white nail polist to cover up the brown stains from the old lamps. As for the sound quality i am not at all impressed a Harman Kardon 330c sitting next to it puts it to shame. anyway another Yamaha cr-2020 lives again. i also added extra heat sinks to the two regulator transistors on the power supply.
and made a mess. after a complete power supply recap and a correct relay and the Yamaha modifications resistor upgrade no relay click at power up. measuring the +25 volts was good but the -25 volt line was being pulled down to -2 volts. short on the -25 volt line was traced down to tr753 or tr754 i forget which one they are on the pre mod. e board i replaced both and she fired up and went to singing.as for the panel lights the Yamaha engineers should have been fired on this receiver. Pitiful to say the least i removed the green filters on the watt meters and tuning pointer use white nail polist to cover up the brown stains from the old lamps. As for the sound quality i am not at all impressed a Harman Kardon 330c sitting next to it puts it to shame. anyway another Yamaha cr-2020 lives again. i also added extra heat sinks to the two regulator transistors on the power supply.