I think I've seen posts of people going up to 27.5mhz and starting to have problems. Mine is overclocked to 25mhz with no problems. I have never read of people having problems at 25mhz, though I'm sure it has happened. Generally the stock 20mhz CPUs don't have a problem at 25mhz.
Many people use an ATX extension cable to be able to power the board outside of the chassis for diagnostic work, that might eliminate the need for the RGB->HDMI dongle, though I do see how that would be a nice setup.
I plugged in a stereo headset, the sound comes out of both sides, and does not come out of the internal speaker at all while the headset is plugged in.
I have done both, same results. I first bodged term power from the external DB25 to the internal connector, then removed the bodge and powered the MacSD through the mini-USB plugged into a wall adapter.
Edit: I'm not sure if it is relevant, but I also do not get this sound if I am using an...
Do you have any thoughts on why this only happens with my MacSD, and not with a hard drive? With a hard drive hooked up if I put my ear right up to the speaker I can hear the same noises but very, very quietly. They are only loud with the MacSD.
These are the caps I used (link). The ESR for these is 30 mOhms, This seems low compared to the 800 mOhms of these tantalums (link) that seem to be the go-to for most recaps, but I know very little about caps.
Thanks for the info, I'll look up the caps I ordered. Is this something that could be caused by cap electrolyte that wasn't thoroughly cleaned? I scrubbed the board with IPA and a toothbrush, and I think this one soaked in IPA for a while too, but it didn't go into an ultrasonic cleaner.
Here is a video I took with my phone, if you turn the volume up you can hear the noises pretty clearly. The buzzing sound at the beginning is what I hear when moving the mouse around, then the noises after that are a result of opening a couple folders and opening the Apple menu.
I just installed a MacSD internally in my IIsi and have some strange audio interference. The speaker makes noises corresponding with SCSI/CPU activity. It is hard to describe the noises, but it is like a combination of squeals and clicks. The noises line up with the SCSI activity, and moving the...