Krell KSA-200S dont turn off

[AdamZ]

Hello guys.
Yesterday it happened for the second time in a few days that I got my KRELL KSA-200S
not turn off. I pressed the power button but nothing happened. I need to cut off the power and the amplifier turned off. Now I have switched on and off 2x and everything works.
Did any of you have this problem before? Is it getting worse? What can I do? Where is the power switch located inside the Amp? because at the Front Pannel is only this small Button.
Thank you and have a nice day.

 

[analogsa]

I have not worked on this particular amp, so please take this with a pinch of salt.

The logic board behind the front fascia controls the soft start circuit with a relay. Some component there has gone off spec, most likely a cap but can also be a resistor, cold solder joint, etc. Impossible to tell from a distance. It will require a repair at some point. It is not hard to take the board out and avoid shipping the entire amp.

 

[AdamZ]

OK. Thank you.
that gives me some hope that it is not a very big problem.
T

 

[analogsa]

It is not. A qualified tech should be able to sort this out in a couple of hours tops.

 

[microstrip]

If it was an unique event most probably the problem was due to a mains transient or glitch that upset the power on/off control system, but did not switch it off. This situation can happen in equipment having a logic control board, such as your KSA200s , and even in our home appliances or computers connected to the mains.

One Audio Research preamplifier I have owned was particularly sensitive to this situation, but a firmware upgrade solved the problem.