Hi,
I have a problem with my old mission cyrus one.
Two weeks ago the right output stoped working. I continued using it and now also the left doesn´t work anymore. It didn´t stop immediately. At first it was some kind of distortion and than it stoped completly.
The fuses are ok, the headphone-output still works.
I read in this thread that one thing to do is to replace some caps.
Would that be worth trying in my case?
Or is it more likely that the transistors are blown up, like I read here?
Any other ideas, what could be the problem?
I have some knowledge in working with electronics and soldering. I´d like to try to repair it myself if possible. But I never repaired a amplifier...
Thanks so much for help!
I have a problem with my old mission cyrus one.
Two weeks ago the right output stoped working. I continued using it and now also the left doesn´t work anymore. It didn´t stop immediately. At first it was some kind of distortion and than it stoped completly.
The fuses are ok, the headphone-output still works.
I read in this thread that one thing to do is to replace some caps.
Would that be worth trying in my case?
Or is it more likely that the transistors are blown up, like I read here?
Any other ideas, what could be the problem?
I have some knowledge in working with electronics and soldering. I´d like to try to repair it myself if possible. But I never repaired a amplifier...
Thanks so much for help!
The headphone-output is direct drive by the power amp, the fuses are ok, so that your amp should be ok.
Maybe PCB traces crack or speaker output posts connection broken, please check and test them.
Maybe PCB traces crack or speaker output posts connection broken, please check and test them.
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Replacing parts in hope is a recipe for disaster. The first steps are to take some voltage readings when the amp is in the faulty state. The three basic things to check are:
1/ That all the power supplies are of the correct voltage.
2/ Check the DC offset of the faulty channel.
3/ Check the standing quiescent current or bias current in the output transistors of the faulty channel.
Those basic steps have to be taken before doing anything else.
As to the headphones working... well they only present a really light load and there are some scenarios where they would appear OK and the speaker feed not OK.
1/ That all the power supplies are of the correct voltage.
2/ Check the DC offset of the faulty channel.
3/ Check the standing quiescent current or bias current in the output transistors of the faulty channel.
Those basic steps have to be taken before doing anything else.
As to the headphones working... well they only present a really light load and there are some scenarios where they would appear OK and the speaker feed not OK.
One thing that often fails on these amps is some round, dark red coloured capacitors with "ROE" written on them. There is one in the feedback path which causes allsorts of issues. Replace all of them.