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Louie, Technician
Category: Consumer Electronics
Satisfied Customers: 12577
Experience:  25+ yrs. experience in the field and 5+ yrs. online, down to component level.
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Louie. Same issue with protect mode, my amplifier is Harman

Customer Question

Hello Louie. Same issue with protect mode, my amplifier is Harman Kardon HK3480. Reset didn't work as I have the dame issue after doing it. Do you have any idea? Here following the description: 1 speaker don't work. If no speakers connected I get thé protect mode when starting the amplifier. If 1 speaker connected also. If 2 speakers connected then it works but only sound in 1 outpout. Tried to connect the input on MAIN IN and same issue (sound controller don't works then).
Any idea? For much information, the speaker that don't works always receive a zzzzzzzz sound.
Submitted: 11 months ago.
Category: Consumer Electronics
Expert:  Pete replied 11 months ago.

Hi, I'm Pete. Welcome to JustAnswer! I'm reviewing your question now, and will post back with your reply ASAP.

Expert:  Pete replied 11 months ago.

Norbert, what happens if you swap the speakers around?

This will help determine if the problem is due to a speaker problem or amplifier problem...

Customer: replied 11 months ago.
Hello, I did many test, it is the amplifier for sure. I switched speakers, cables, always same issue with same speaker side..
Customer: replied 11 months ago.
Speakers 1 output and speakers 2 outpout have also the same issue...
Customer: replied 11 months ago.
I can also send you the manual if you need to check it
Expert:  Pete replied 11 months ago.

Do you have the service manual?

Are you planning on carrying out any electronic repairs yourself?

Customer: replied 11 months ago.
Hello, I'm planning to repair it by myself, that's why I contact you. I have the manual but cannot send from this page, maybe email?
Expert:  Pete replied 11 months ago.

If you cannot attach it here then you can email it to***@******.***

Customer: replied 11 months ago.
Manual have been sent, please confirm the correct reception.
Customer: replied 11 months ago.
On page 19, B6 you can see the MAIN IN. I've connected entry signal there and same issue. It means that all other entry and circuit before this point ils discarted right? You van also check page 20, you will find where this entry goes...
Customer: replied 11 months ago.
Just realized that phones exit is also NOT working. Same zzzzzzzzz that on the speaker side that doesn't work. I believe the issue of speaker side ans phones exit came at the same time....
Customer: replied 11 months ago.
What's strange is why when speakers not connecte I cannot start the amplifier and I get straitgh the protect mode...
Customer: replied 11 months ago.
Also important, when I start the amplifier with speakers connected I can leasen a medium crash sound on the speaker way that's not working...
Expert:  Louie replied 11 months ago.

Hi Norbert, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.

Initially, the described symptom almost always is an internal hardware issue. Are you then considering a DIY (do-it-yourself) repair approach? If yes, do you have access to and familiar with a multi-meter and even a soldering iron?

Customer: replied 11 months ago.
Hello Louie, thanks for your reply. I will repair by myself yes, that's why i contacted you. I have a multimeter and also a soldering iron. The problem it's that I'm not at home till friday night. I hope that with your help I will be able to repair it. Did you read my other messages to Pete? Which components should I check?
Expert:  Louie replied 11 months ago.

Great on the DIY Norbert!

And I understand; Friday then or when conveniently able.

Let's start with the basics, check the outputs. Proposed preliminary checks on (if have not been done):

  • • check for the presence & consistency of -15V to speaker relays RY31 & RY32;
  • • test for protect voltage at the collector of Q332;
  • • verify BIAS voltage;
  • • check the output Darlington transistor pairs of Q319 & Q321 and Q320 & Q322.

A friendly reminder: voltage measurements by its very nature requires the h/k to be plugged in and turned on. It is therefore LIVE! Please exercise due care and caution.