Hey ya'll.
I had recently acquired a Performa 578 off of market place and brought it home with me, it does function, and despite being a little bit dirty, it was in otherwise good condition. While it did work and boot to MacOS 7.1, it made this awful squealing noise the entire time it was powered on. I did open it up and take a listen, and it appears to be coming from the section of the motherboard where two transformers live (pic related). I have recapped most of the motherboard as some of the capacitors were just starting to leak. I did all of them apart from the capacitors under the RF shielding.
However the machine still makes the noise, and I'm unsure of what is causing it. The squealing starts from the moment I hit the soft power on the keyboard and seems to vary with system load. Like if I opened a large image, I could hear a pitch shift difference between the CPU processing data and the CPU waiting for data to load in.
I've attached an image of the board (shamelessly stolen from this thread https://tinkerdifferent.com/threads/mac-lc-575-analog-board-recap-guide-photos.4463/) with the red marking where I have yet to recap, and the blue marking where I heard the noise with the case apart. Along with a video with the noise.
Any ideas? I'm lost and unsure of where to go or what this means. Any help or advice would be appreciated.
I had recently acquired a Performa 578 off of market place and brought it home with me, it does function, and despite being a little bit dirty, it was in otherwise good condition. While it did work and boot to MacOS 7.1, it made this awful squealing noise the entire time it was powered on. I did open it up and take a listen, and it appears to be coming from the section of the motherboard where two transformers live (pic related). I have recapped most of the motherboard as some of the capacitors were just starting to leak. I did all of them apart from the capacitors under the RF shielding.
However the machine still makes the noise, and I'm unsure of what is causing it. The squealing starts from the moment I hit the soft power on the keyboard and seems to vary with system load. Like if I opened a large image, I could hear a pitch shift difference between the CPU processing data and the CPU waiting for data to load in.
I've attached an image of the board (shamelessly stolen from this thread https://tinkerdifferent.com/threads/mac-lc-575-analog-board-recap-guide-photos.4463/) with the red marking where I have yet to recap, and the blue marking where I heard the noise with the case apart. Along with a video with the noise.
Any ideas? I'm lost and unsure of where to go or what this means. Any help or advice would be appreciated.
