Harman Kardon AVR 270 Buzzing inductor

[bluebear]

Hi

I´m trying to find why my HK AVR 270 shuts down with 5 speakers hooked up and increasing volume to about -17dB.

I´ve noticed that a buzz is coming from the unit, not the speakers, and increases when volume is turned up. The humming is annoyingly noticeable. Opened it up and I´m fairly certain that its coming from the inductor CLZ9Z148Z, attached with leads to the primary side CN91 connector.

C983 and C984 as previously been replaced.

How regular is it that inductors fail and would it manifest in this kind of way?

Cheers,
B.

[budm]

Re: Harman Kardon AVR 270 Buzzing inductor

I do not see 'inductor CLZ9Z148Z' in your pictures.
Are you using the same 5 speakers but did not have the hum in the past?
Service manual:

[bluebear]

Re: Harman Kardon AVR 270 Buzzing inductor

do not see 'inductor CLZ9Z148Z' in your pictures.

Sry, I was'nt clear that it was on the last picture, mounted on the frame.
It is filed as a inductor PFC in the service manual.

Cheers,
B.

[bluebear]

Re: Harman Kardon AVR 270 Buzzing inductor

Are you using the same 5 speakers but did not have the hum in the past?

I have tried with to different sets, 3 speakers and 5 speakers. I did notice the annoying hum, could hear it across the room. With 5 it shutdown on -17dB.

When looking at the photo, I notice some gunk in the inductor case, hmm.
Cheers, B.

[zlatko.temelkovski]

Re: Harman Kardon AVR 270 Buzzing inductor

I do not see 'inductor CLZ9Z148Z' in your pictures.
Are you using the same 5 speakers but did not have the hum in the past?
Service manual:

I had the same problem, changed both ceramic capacitors (mosfets were OK). It works great, but when I connect it to 5 speakers there is quite a loud hum, I think from the inductor that is screwed to the chassis. The buzzing is gone on headphones. How do I solve this problem?