Hi need some help on Mission Cyrus PSX amps and thought someone may be able to help me as I am a bit of an amatuer.
I have a cyrus psx combined with the cyrus II. When I swithch on the power the 2 internal 4A fuses in the psx blow.
When I switch the power on on the cyrus II, the 2 fuses in it don't blow until it is conected to the psx. This seems to tell me there is a problem with the cyrus psx? Can you help me find the problem? As I am keen to understand why rather than just take it to some repair shop and never know.
Thanks
Darin
I have a cyrus psx combined with the cyrus II. When I swithch on the power the 2 internal 4A fuses in the psx blow.
When I switch the power on on the cyrus II, the 2 fuses in it don't blow until it is conected to the psx. This seems to tell me there is a problem with the cyrus psx? Can you help me find the problem? As I am keen to understand why rather than just take it to some repair shop and never know.
Thanks
Darin
Re: not making much sense there carlos
Destroyer speaks English as a second language, so although his replies may seem cryptic, they do actually make sense!
He is suggesting that the problem is with the power transistors in the PSU, they have blown, and that is causing the fuses to go.
I personally know just enough to be dangerous as regarding high power PSUs, but if your patient I'm sure someone will be along to help soon!
Darin P-B said:
Destroyer speaks English as a second language, so although his replies may seem cryptic, they do actually make sense!
He is suggesting that the problem is with the power transistors in the PSU, they have blown, and that is causing the fuses to go.
I personally know just enough to be dangerous as regarding high power PSUs, but if your patient I'm sure someone will be along to help soon!
There might be a problem with the amp as well. A fault on the amp (short circuit somewhere) could have caused the psu to fail.
If the psu is not regulated the component/s most likely to fail would probably be the rectifer diodes / bridge. With the power off check these using a multimeter with a diode test setting.
If the psu is regulated the number of possible failure modes makes remote diagnosis somewhat difficult.
If the psu is not regulated the component/s most likely to fail would probably be the rectifer diodes / bridge. With the power off check these using a multimeter with a diode test setting.
If the psu is regulated the number of possible failure modes makes remote diagnosis somewhat difficult.
Sorry darin, but pinkmouse got the whole idea
Not first time people think i was doing critics or something alike.
Really sometimes i made small jokes and also put in parenthesis (hahaha) to make people understand the way is written.
But normally not, i like to be helpfull, unfortunattelly no enough knowledge to help many people.
I think my smiling face, in photo, can be the trouble.... i am thinking in change it... this smile can be hard for some people....i will put something more serious because someone told this is ironic face.
When this picture was taken, my small and loved daughter was learning how to take pictures with old film machines.... the smile is a kind way to look at her.... an acceptance smile because she could, so small girl, do this job without problem... also is a proudy smille because i think my daugther is wonderfull.
But, someone can think this is is a smilling to you!.... this smile means, I AM SMILLING TOGETHER WITH YOU, ACCEPTING YOU!
Sorry again... speak portuguese.... me speak indian, me go!
Carlos
Not first time people think i was doing critics or something alike.
Really sometimes i made small jokes and also put in parenthesis (hahaha) to make people understand the way is written.
But normally not, i like to be helpfull, unfortunattelly no enough knowledge to help many people.
I think my smiling face, in photo, can be the trouble.... i am thinking in change it... this smile can be hard for some people....i will put something more serious because someone told this is ironic face.
When this picture was taken, my small and loved daughter was learning how to take pictures with old film machines.... the smile is a kind way to look at her.... an acceptance smile because she could, so small girl, do this job without problem... also is a proudy smille because i think my daugther is wonderfull.
But, someone can think this is is a smilling to you!.... this smile means, I AM SMILLING TOGETHER WITH YOU, ACCEPTING YOU!
Sorry again... speak portuguese.... me speak indian, me go!
Carlos
I can imagine that you cannot just connect a PSX to a Cyrus amp.
I think the PSX is a power supply for the power output stage.
What happens may be that you connect 2 power supplies in parallel, which is not allowed.
Inside the Cyrus amp you should disconnect the power supply from the final stage, and then connect the PSX.
I hope this helps.
I think the PSX is a power supply for the power output stage.
What happens may be that you connect 2 power supplies in parallel, which is not allowed.
Inside the Cyrus amp you should disconnect the power supply from the final stage, and then connect the PSX.
I hope this helps.
Thanks for the replies, and sorry Carlos if I took you the wrong way - new to this forum.
I think I may have got the 2 Cyrus bits mixed up so will correct here-
I have a cyrus II (integrated stereo amplifier) combined with the cyrus psx (external DC power supply for Cyrus II). The Cyrus psx plugs in to the Cyrus II (blue cord female 3 pin +40 -40 Volts DC). Both units also have their own pwer supply cables from mains.
When all conected and I swith on the power the 2 internal 4A fuses blow in each of the Cyrus psx and the Cyrus II. With the 2 fuses blown in each unit both power lights still come on at the front.
When I switch the power on on the Cyrus psx, the 2 fuses in it don't blow until it is conected to the Cyrus II. This seems to tell me there is a problem with the cyrus II?
Can you help me find the problem? As I am keen to understand why rather than just take it to some repair shop and never know.
Hopefully it is now a bit clearer for somebody to help me.
Thanks
Darin
I think I may have got the 2 Cyrus bits mixed up so will correct here-
I have a cyrus II (integrated stereo amplifier) combined with the cyrus psx (external DC power supply for Cyrus II). The Cyrus psx plugs in to the Cyrus II (blue cord female 3 pin +40 -40 Volts DC). Both units also have their own pwer supply cables from mains.
When all conected and I swith on the power the 2 internal 4A fuses blow in each of the Cyrus psx and the Cyrus II. With the 2 fuses blown in each unit both power lights still come on at the front.
When I switch the power on on the Cyrus psx, the 2 fuses in it don't blow until it is conected to the Cyrus II. This seems to tell me there is a problem with the cyrus II?
Can you help me find the problem? As I am keen to understand why rather than just take it to some repair shop and never know.
Hopefully it is now a bit clearer for somebody to help me.
Thanks
Darin
Not kidding, check this please
You have two power cords.... three pins.... positive, negative and ground.... inside amplifiers may have those grounds soldered to the mains chassis... and audio sometimes, suspended from earth with 10 ohms resistor.
Lets imagine one of those cables with the ground broken inside... the ground will be made by the audio cables ground.. sometimes suspended ground.... when this happens, sometimes amplifier oscilates for microseconds and high consumption creating, lets see, some high frequency, short period oscilations.... this way fuses blow, because overcharge... lights remais because this do not affect them because if one fuse remains, you will have energy to regulator to keep lamps on (maybe small consumption leds...i do not know).
Also leakage..... measure AC in cabinet, in metal enclosure... one multimeter tip at metal and other point between your fingers and press it...measure if you have AC....having you have a damage transformer that is passing AC to the ground.
Just imagine those crazy things...no problem, if i told an foolish, will be better, just because hi knowledge people will not allowed such a foolish idea remains for a long time and will run to correct.
This way, will help all of us.
All OK!.... no more troubles in the world.... me speak english strange (sometimes as indian does)....my picture smile is also strange..one thinks is sadic, other thinks is kind, other thinks is ironic... how can i control their minds?.... i cannot!. So, some confused conclusions can be expected. Its all rigth.
Thank you for a new chance.
Carlos
You have two power cords.... three pins.... positive, negative and ground.... inside amplifiers may have those grounds soldered to the mains chassis... and audio sometimes, suspended from earth with 10 ohms resistor.
Lets imagine one of those cables with the ground broken inside... the ground will be made by the audio cables ground.. sometimes suspended ground.... when this happens, sometimes amplifier oscilates for microseconds and high consumption creating, lets see, some high frequency, short period oscilations.... this way fuses blow, because overcharge... lights remais because this do not affect them because if one fuse remains, you will have energy to regulator to keep lamps on (maybe small consumption leds...i do not know).
Also leakage..... measure AC in cabinet, in metal enclosure... one multimeter tip at metal and other point between your fingers and press it...measure if you have AC....having you have a damage transformer that is passing AC to the ground.
Just imagine those crazy things...no problem, if i told an foolish, will be better, just because hi knowledge people will not allowed such a foolish idea remains for a long time and will run to correct.
This way, will help all of us.
All OK!.... no more troubles in the world.... me speak english strange (sometimes as indian does)....my picture smile is also strange..one thinks is sadic, other thinks is kind, other thinks is ironic... how can i control their minds?.... i cannot!. So, some confused conclusions can be expected. Its all rigth.
Thank you for a new chance.
Carlos
I worked out where all the transistors are (quite a few!) Not too sure where the output transistors are. But tested resistance and only seemed to get readings on the larger ones screwed to the heatsink ( 8 large and 2 small). Of the 8 large 6 showed a reading of about 120 and 1 was 0.5 and the other 1.5. The 2 smaller ones did not seem to give a reading - meter stayed at 1. The other little ones scattered about seemed to give a very breif reading and then just 1.
So does this mean the 2 on the heatsink need repacing? If it does and I replace them will they just fail again due to another problem somewhere else or do they just fail by themselves?
Really appreciate your help
Cherers
Darin
So does this mean the 2 on the heatsink need repacing? If it does and I replace them will they just fail again due to another problem somewhere else or do they just fail by themselves?
Really appreciate your help
Cherers
Darin
Even though only two of the output transistors may be blown, it usually means the others have had quite an overload so all 8 should be replaced as a set. Sometimes this sort of fault can be caused by shorted speaker cables, or could have been the result of some smaller component failure. It is also quite probable that other components could have failed due to the output transistors shorting.
Best advice would be to seek the services of someone with power amp knowlege and decent test equipment.
Cheers
Best advice would be to seek the services of someone with power amp knowlege and decent test equipment.
Cheers
Centauri gives good advice
I replied to your email Darin, but you did not respond back to me...
Testing with a resistance meter is not really appropriate and can give different results depending on what meter you use and which way round you get the probes. You need to do a diode test, you can find how to do this in a basic electronics text book such as Horowitz and Hill (check your local library).
It would be very useful to know if the amp just died, or did it go under loud playing, plugging anything in or out, or shorted cables? This may have an impact on what else has blown.
I can deduce from your description of there being 8 transistors on the heatsink that you have an early Cyrus 2. Don't waste your time contacting Cyrus, their support is useless if they bother to respond at all.
It's quite likely that the two you measured as lower than the others are blown, but to be sure you need to diode test all of them and also the driver transistors.
However, if two have blown I would play safe and replace all the output transistors and their drivers. I even replaced the pre-drivers in the one I did. If you wanted to skimp a little you could just replace the output transistors and the drivers of the channel with the low measured devices in. The drivers are MJE343 and MJE353 and can be replaced with MJE340 and MJE350 which you should be able to find anywhere. The output devices are marked with Cyrus own cryptic marking, TIP41C (note must be this exact marking not A or B type) should be a suitable replacement.
I replied to your email Darin, but you did not respond back to me...
Testing with a resistance meter is not really appropriate and can give different results depending on what meter you use and which way round you get the probes. You need to do a diode test, you can find how to do this in a basic electronics text book such as Horowitz and Hill (check your local library).
It would be very useful to know if the amp just died, or did it go under loud playing, plugging anything in or out, or shorted cables? This may have an impact on what else has blown.
I can deduce from your description of there being 8 transistors on the heatsink that you have an early Cyrus 2. Don't waste your time contacting Cyrus, their support is useless if they bother to respond at all.
It's quite likely that the two you measured as lower than the others are blown, but to be sure you need to diode test all of them and also the driver transistors.
However, if two have blown I would play safe and replace all the output transistors and their drivers. I even replaced the pre-drivers in the one I did. If you wanted to skimp a little you could just replace the output transistors and the drivers of the channel with the low measured devices in. The drivers are MJE343 and MJE353 and can be replaced with MJE340 and MJE350 which you should be able to find anywhere. The output devices are marked with Cyrus own cryptic marking, TIP41C (note must be this exact marking not A or B type) should be a suitable replacement.
Thanks all for replys
Now these replacements transistors that aren't cyrus ones does this affect anything - such as quality of sound or amplification?
The seemingly faulty ones have the marking 644N at the top and then CYRUSPT - 7 at the bottom. And the other one (right next to it) 649N at top and CYRUSPT - 7 at bottom.
What sort of cost am I up for do you think - if it's just the transistors?
I appreciate everyones help on this... I now think it's time to hand over to a profesional.
Cheers
Darin
Now these replacements transistors that aren't cyrus ones does this affect anything - such as quality of sound or amplification?
The seemingly faulty ones have the marking 644N at the top and then CYRUSPT - 7 at the bottom. And the other one (right next to it) 649N at top and CYRUSPT - 7 at bottom.
What sort of cost am I up for do you think - if it's just the transistors?
I appreciate everyones help on this... I now think it's time to hand over to a profesional.
Cheers
Darin
Re: not making much sense there carlos
You Brits can't rest at the fact that a non-native takes the effort to learn your Language... you have to pi$$ on it when it doesnt fit your definition of being non-cryptic. Lets try and be a little appreciative... Carlos is a cool dude!
Carlos man, you are ok, don't worry about any criticism, your enthusiasm and contributions are welcome and appreciated.
Darin P-B said:
You Brits can't rest at the fact that a non-native takes the effort to learn your Language... you have to pi$$ on it when it doesnt fit your definition of being non-cryptic. Lets try and be a little appreciative... Carlos is a cool dude!
Carlos man, you are ok, don't worry about any criticism, your enthusiasm and contributions are welcome and appreciated.
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