A tale of two amplifiers - both Harman Kardon AVR 3550

[rwnano]

I have TWO (2) of these Harman Kardon AVRs
https://www.hifiengine.com/manual_library/harman-kardon/avr3550.shtml
One of these units is working perfectly well in two channel STEREO mode and other modes. I use this regularly to listen to music.

The other unit has a problem:
The other one is working in 5 channel surround sound mode - BUT - only CENTER channel & Surround LEFT & Right channels are working and giving an output of Sound.
FRONT Left and FRONT Right channels are not working and not outputting sound.
Should I get it repaired? I got the reference of one Mr Jagmohan who is a good repairwallah in Kalkaji, New Delhi.
Jagmohan AVR repair Kalkaji Electronico
Or should I junk it? I just came in possession of it recently, this weekend.

 

[mbhangui]

I have TWO (2) of these Harman Kardon AVRs
https://www.hifiengine.com/manual_library/harman-kardon/avr3550.shtml
One of these units is working perfectly well in two channel STEREO mode and other modes. I use this regularly to listen to music.

The other unit has a problem:
The other one is working in 5 channel surround sound mode - BUT - only CENTER channel & Surround LEFT & Right channels are working and giving an output of Sound.
FRONT Left and FRONT Right channels are not working and not outputting sound.
Should I get it repaired? I got the reference of one Mr Jagmohan who is a good repairwallah in Kalkaji, New Delhi.
Jagmohan AVR repair Kalkaji Electronico
Or should I junk it? I just came in possession of it recently, this weekend.

There are relays which switch on and connect your speaker output to the amp output. Both Left and Right channel gone at the same time, it seems unlikely two amplifier channel went bad at the same time. It looks like the relay which switches on the right + left front channels is not switching on.

 

[rwnano]

There are relays which switch on and connect your speaker output to the amp output. Both Left and Right channel gone at the same time, it seems unlikely two amplifier channel went bad at the same time. It looks like the relay which switches on the right + left front channels is not switching on.

thank you!

 

[rwnano]

Bhangui sir, one more question: when I cycle through the surround sound modes: 5 channel, logic 7 , dts dolby and surround off; on the logic 7 and dts dolby modes, the same center channel and surround sound channel speakers, with the same input Media give a scratchy sound rather than the clear sound that issues from the speakers when 5 channel surround sound mode is active .
Any feedback on this topic please? May be one more board is having a problem apart from the relay switches mentioned above .

 

[mbhangui]

Bhangui sir, one more question: when I cycle through the surround sound modes: 5 channel, logic 7 , dts dolby and surround off; on the logic 7 and dts dolby modes, the same center channel and surround sound channel speakers, with the same input Media give a scratchy sound rather than the clear sound that issues from the speakers when 5 channel surround sound mode is active .
Any feedback on this topic please? May be one more board is having a problem apart from the relay switches mentioned above .

Post the video of the scratching sound

 

[availlyrics]

U can check the ouput by tapping those relays with the amp ON(CAREFUL!) with any non-conductive object like a pen

 

[mbhangui]

The relay not switching on can mainly be due to two reasons
1. Relay is bad
2. The microprocessor which detects faults and switches on the relay is not switching on the relay

 

[mbhangui]

U can check ouput by tapping the relays with the amp ON(CAREFUL!) with any non-conductive object like a pen

Ha ha. I do that with my meter room ACCL. It has a relay that switches on to generator or the main supply. It works most of the time when the armature gets stuck