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How do you drain stored energy on a yamaha cr2020

Thanks again !! You've been a major help... the unit is still running ! Enough to drive a person crazy.. have a good night and thank you so much
 
The main filter caps in these have a 4.7Kohm resistor across them, which will drain them down to an acceptable level in 30 seconds or so after the unit is switched off, if you have the time to wait.
 
Bob Chieldon said:
The main filter caps in these have a 4.7Kohm resistor across them, which will drain them down to an acceptable level in 30 seconds or so after the unit is switched off, if you have the time to wait.
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avionic said:
There are two bleeder resistors across the two large caps . Two 4.7KΩ 2 watt resistors will bleed down the cap voltage when power is disconnected. You can monitor this voltage by measuring the voltage on the output transistor metal cases (collector) and chassis ground. The output transistors are mounted on the large aluminum heatsinks centered within the receiver.
You only need to monitor one channel.. Each channel shares the same power supply.

One of the outputs on each heatsink will have a negative voltage and the other one will have a positive voltage.

2N3771-NPN-Power-Transistor-Pinout.jpg
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Thank you.. is this multimeter adequate ? I turned it to dcv, and it was taking forever for any reading to drop.20220201_163234.jpg
 
Bleeder resistors may have been deleted or have drastically changed value.. Do you have any large say 5 watt resistors on hand ?
 
Nashou66 said:
I use a 330 ohm 2 watt resister( just cause I had it handy) that I hold with a pair of pliers across the legs of the caps to be discharged
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Get a couple alligator clipped jumper wires and a 300-500Ω , 2 - 5 watt resistor. Instead of hooking up your meter to the transistor case and chassis ground. Hook up the resistor instead. That will drain it PDQ..
 
avionic said:
Bleeder resistors may have been deleted or have drastically changed value.. Do you have any large say 5 watt resistors on hand ?
Click to expand...

Hi Dave, no I don't. I'm a full blown beginner in this field. It seems like it's slowly draining itself.. my readings are -5.3 and the opposite side is at 4.120220201_213327.jpg
 

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avionic said:
Get a couple alligator clipped jumper wires and a 300-500Ω , 2 - 5 watt resistor. Instead of hooking up your meter to the transistor case and chassis ground. Hook up the resistor instead. That will drain it PDQ..
Click to expand...
This method would take less than 5 minutes..
 
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