Berning-EA2101-pwr-sch维修电路原理图.pdf

The failure prone parts in the EA-2101 are the four 150K resistors in the feedback sensing. Early versions used carbon film resistors that tended to increase in value, or go open completely, causing the output voltage of the power supply to increase until something else failed. Later versions of the amp used 1 W metal film resistors which have not shown failures. Any amps that have been returned to Berning for any kind of service have had these resistors changed. When this amp is serviced, the 700 volt output of the power supply should be checked. If it is high, more than 720 volts, these resistors should be checked. Related failures caused by over voltage are the capacitor bank, voltage-equalizing resistors, and the HR307 diodes. Bias measurements can be made by measuring across the 15 ohm resistors that are mounted along the front edge of the audio boards. These can be accessed via holes in the bottom of the chassis, and the correct voltage is 100mV. This amplifier should be able to deliver at least 100 watts per channel. RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库