Cyrus One resistor heating problem

[Rahand]

Hello everyone,
I have a problem with my amplifier (Cyrus one), when I turn on the power switch, both resistors 119,120 rapidly heats up.

Can any one help?

 

[huggygood]

these are the power supply resistors of the LED, unsolder them, check their values (100ohm), also check all the capacitors around, especially the small uF values,also +Vcc,-Vcc,+Vreg and -Vreg

 

[ulogon]

both resistors 119,120 rapidly heats up.

Did you even notice that the "white" cable in the foreground appears burnt?

 

[Hicoco]

I had the same issue see : https://www.diyaudio.com/community/threads/advice-needed-blown-cyrus-two.345357/#post-7563300

 

[Rahand]

Yes, the white one burnt

 

[as_audio]

Always check R121, connects signal ground to chassis.
A stronger resistor is preferred.

 

[huggygood]

Yes, the white one burnt

The grey from the PT too

 

[Rahand]

Thanks for your advice

 

[cabirio]

Note that, at least in mine which is the TOG version, these are actually 1k5 rather than 100R, despite what the service manual says. That makes a lot more sense given that the LED circuit is connected directly across one transformer secondary.

 

[cabirio]

I just found this at the beginning of the SM, even though the final section is the same for the 07 and TOG versions. I guess they fixed it with the more appropriate 1k5 resistors (standard 1/4W or 0.6W by looks / size) but didn't bother including a new schematic and component list for the latter version.