I'm working on one of these --- it powers up but all that's there is a hummmm.
I tried swapping out the filter caps in the power supply, also have on hand 4558s and a TL074 and tried changing them with no luck. Resoldered both boards. So what am I left with? The 87476? Are there any subs that can be used for this IC? If there's an open component or a shorted transistor would it power on at all? I'm not running it through the speaker, I'm using a known good speaker. '
Does anyone have any suggestions?
pete
I tried swapping out the filter caps in the power supply, also have on hand 4558s and a TL074 and tried changing them with no luck. Resoldered both boards. So what am I left with? The 87476? Are there any subs that can be used for this IC? If there's an open component or a shorted transistor would it power on at all? I'm not running it through the speaker, I'm using a known good speaker. '
Does anyone have any suggestions?
pete
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