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Old 2nd February 2013, 07:31 AM   #11
lowpoke is offline lowpoke  Australia
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Quote:
Originally Posted by megajocke View Post
Isn't it the one right there inside the red rectangle, next to the aluminium clad resistor?

The failure might very well be in the soft start circuit, causing the relay to buzz.
This would be good news right?
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Old 2nd February 2013, 08:09 PM   #12
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Quote:
Originally Posted by megajocke View Post
Isn't it the one right there inside the red rectangle, next to the aluminium clad resistor?.....
The black square block? That could well be the small delay switch relay but 30A/250 VAC rated? I am not so sure there. Still, a bad relay any size can certainly buzz.

Yes lowpoke, that would be simple for the repairer, if he can get suitable replacement parts.
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Old 3rd February 2013, 05:56 AM   #13
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Ah, yes this seems to be the triac version, with a lower rated relay. Looking at the wiring diagram you have the three wires to the triac exiting the board right beside the resistor.
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Old 22nd February 2013, 12:04 PM   #14
lowpoke is offline lowpoke  Australia
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UPDATE:
So I finally got my amp back from the workshop. Apparently the small black caps to the upper right of the red rectangle (in the image in my first post) were leaking. There were also apparently some dry joints that were also resoldered on that board.
They gave me the original caps back, but they looked perfectly good. No physical signs at all of any leakage.

Anyway, amp is working beautifully again now and the repair bill was totally reasonable!
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Old 22nd February 2013, 03:24 PM   #15
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Quote:
Originally Posted by lowpoke View Post
UPDATE:
So I finally got my amp back from the workshop. Apparently the small black caps to the upper right of the red rectangle (in the image in my first post) were leaking. There were also apparently some dry joints that were also resoldered on that board.
They gave me the original caps back, but they looked perfectly good. No physical signs at all of any leakage.

Anyway, amp is working beautifully again now and the repair bill was totally reasonable!
Leaky caps, That is nothing new since this amp is more than 20 years old. I would change "all" those electrolytic caps using high grade and temp like 105c caps. To check those caps you will need an E.S.R meter, most of caps look good to the eye but as soon as you put them under the E.S.R meter...all changes!
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