501 has a loud whistle

[wjwatt123]

Does anyone know why a 501 would have a loud whistling sound coming from the main board. I removed the power supply and plugged it in off the board and it was quiet, then I removed the hard drive and it still made the sound.

[wjwatt123]

Nevermind it was the power supply when it was put under load, I had another one from an old 510 that worked fine.

[Wendell980]

might be a noisy power transformer you could replace it, the transformer is prolly buzzing because the voltage is causing it to vibrate

[wjwatt123]

Thanks, I'll give it a try

[bud02]

Leaky caps will also whistle, put your finger on them to find the offender.

[wjwatt123]

Thanks for the tip