I wanted to share a quick tip about the sound chip on the Performa / LC 575 and similar Macs. We all know that leaking caps can kill these sound chips. Of course this could also eat away traces on the board and make the sound only partially work.
I had an interesting scenario with a client's 575 board. After replacing the sound chip with a new one... I only got the faintest sound from the headphone jack and nothing from the speakers.
So I checked against my own working 575 board. I found two connections missing, so I ran a trace to solve it (the red cable running from left to right). But that didn't solve it... but I found another. It turns out the connection from the positive side of C1 was not making it to L2. Bridging that connection solved the issue! (This can be seen as the thin red cable running vertically in the photo). Now sound from the headphone jack and the speakers were now loud and clear.
I know this won't solve every issue, but it's suffice to say that the connection between C1 and L1 are pretty important for the sound to work properly. I know these models don't have schematics, so maybe this may help someone in the future.
(And yes, these bodge wires were a mess, don't worry, this was all cleaned up after repair).
I had an interesting scenario with a client's 575 board. After replacing the sound chip with a new one... I only got the faintest sound from the headphone jack and nothing from the speakers.
So I checked against my own working 575 board. I found two connections missing, so I ran a trace to solve it (the red cable running from left to right). But that didn't solve it... but I found another. It turns out the connection from the positive side of C1 was not making it to L2. Bridging that connection solved the issue! (This can be seen as the thin red cable running vertically in the photo). Now sound from the headphone jack and the speakers were now loud and clear.
I know this won't solve every issue, but it's suffice to say that the connection between C1 and L1 are pretty important for the sound to work properly. I know these models don't have schematics, so maybe this may help someone in the future.
(And yes, these bodge wires were a mess, don't worry, this was all cleaned up after repair).
