Karl vd Berg
Super Member
Hi all,
Tried in other places, but no help, so I hope you give me a hand here...
I have an Onkyo TX-84 to service. The 2 main problem was a permanent and annoying "buzz" and a relay (12V) going under protection. I've heard that this 1985 receiver has a common issue with its relays so I decided to change the 2 relays it has in the power amp board....
Ahead:
The amp had no ground connected, so I added a power cord with ground connection at the chassis and stopped to feel that current when I touched the case. The audio "buzz" dropped a lot, but still I could hear it when I switched to another input line in silent moments.
I decided to replace the two main power caps (10,000uF 50V Nichicon VX(M) series) as they were leaking a lot - as you can see from the picture, with two new BC Vishay M 10,000uF 63V.
When I switched it on to test the amp, the 5A fuse blows all the time when I just turn the Volume pot a bit louder...
Checked polarity of power caps, everything seems perfect.
Can it be one of the relays (they have same 12V and 24V as the originals had).
Or maybe one of the caps is in short, but I don't know where...
Listening to very low volume I notice a huge improvement on the bass and dinamics, but once I put the volume a bit higher, the fuse blows up!
Any idea?
Tried in other places, but no help, so I hope you give me a hand here...
I have an Onkyo TX-84 to service. The 2 main problem was a permanent and annoying "buzz" and a relay (12V) going under protection. I've heard that this 1985 receiver has a common issue with its relays so I decided to change the 2 relays it has in the power amp board....
Ahead:
The amp had no ground connected, so I added a power cord with ground connection at the chassis and stopped to feel that current when I touched the case. The audio "buzz" dropped a lot, but still I could hear it when I switched to another input line in silent moments.
I decided to replace the two main power caps (10,000uF 50V Nichicon VX(M) series) as they were leaking a lot - as you can see from the picture, with two new BC Vishay M 10,000uF 63V.
When I switched it on to test the amp, the 5A fuse blows all the time when I just turn the Volume pot a bit louder...
Checked polarity of power caps, everything seems perfect.
Can it be one of the relays (they have same 12V and 24V as the originals had).
Or maybe one of the caps is in short, but I don't know where...
Listening to very low volume I notice a huge improvement on the bass and dinamics, but once I put the volume a bit higher, the fuse blows up!
Any idea?
