Hello,
As a foreword I'm relatively novice with component level audio gear repair. My amplifier stopped producing sound and I currently have no funds to buy a new one so I need any help to repair it. I know "no sound" is one of the most common problem but there were other symptoms so some of you seasoned repairman might able to pinpoint the stuff I have to check. I did download the service manual from manualslib the "no sound checklist" is a bit intimidating.
So i bought it working. First symptom: speaker protection relays on the audio board were clicking really fast. Issue stopped on its own. Then I kept hearing relay clicks during listening then the issue went away. Then once I turned it on then the speaker protector relays were stuck in triggered position and did not release so when I turned on/off my speakers were popping. Then the issue went away. Now it stopped producing sound from any input. I still hear the clicks when it turns on tho. I started to play with volume and one time I had sound for a few seconds but only on full volume then it went silent and is silent ever since.
For whatever reason I thought it my be the relays fault (can it be?), I took out the speaker board with the relays on it but they look pristine. I tried injecting with 8 volts and all firmly clicked. I have some similar spare relays if you guys say so I can replace them. I found some flux marks on the SMPS. Not sure if it is factory or previous repair. No obvious signs of burn marks anywhere. Fuses ok. No shorts, the amp is not turning off in any kind of protection mode.
I would be helpful if you could give me a few tips on what to check first. I have a basic scope in my shop I use for arduino PWMs if I need to probe it. Some photos attached on what I found inside.
Service Manual
As a foreword I'm relatively novice with component level audio gear repair. My amplifier stopped producing sound and I currently have no funds to buy a new one so I need any help to repair it. I know "no sound" is one of the most common problem but there were other symptoms so some of you seasoned repairman might able to pinpoint the stuff I have to check. I did download the service manual from manualslib the "no sound checklist" is a bit intimidating.
So i bought it working. First symptom: speaker protection relays on the audio board were clicking really fast. Issue stopped on its own. Then I kept hearing relay clicks during listening then the issue went away. Then once I turned it on then the speaker protector relays were stuck in triggered position and did not release so when I turned on/off my speakers were popping. Then the issue went away. Now it stopped producing sound from any input. I still hear the clicks when it turns on tho. I started to play with volume and one time I had sound for a few seconds but only on full volume then it went silent and is silent ever since.
For whatever reason I thought it my be the relays fault (can it be?), I took out the speaker board with the relays on it but they look pristine. I tried injecting with 8 volts and all firmly clicked. I have some similar spare relays if you guys say so I can replace them. I found some flux marks on the SMPS. Not sure if it is factory or previous repair. No obvious signs of burn marks anywhere. Fuses ok. No shorts, the amp is not turning off in any kind of protection mode.
I would be helpful if you could give me a few tips on what to check first. I have a basic scope in my shop I use for arduino PWMs if I need to probe it. Some photos attached on what I found inside.
Service Manual
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