Interference With External Monitor-powerbook, whine on tannoy reveals Options

[brettybwoy]

Hello Macmusic folks. I have a very annoying problem. I am using a g4 powerbook 12" (1.25ghz) with an edirol fa 101 firewire interface and tannoy reveal active monitors. When I plug a external vga monitor into the powerbook, I get a high pitched interference on the tannoys. this also happens if i plug in my printer to usb. i have bought a couple of ferrite core rings from Maplin and tried placing them on monitor and firewire cables, to no avail. Anybody know how to cure this? Mac shop said it may be logic board...
PHEW! THANKS. BRETTY

[lepetitmartien]

Do you have an halogen lamp around, a fluorescent lamp?

Is the ground in you house well grounded?

Could you give us a guess of the frequency of the interference?

Are the interface, the reveals, the printer all plugged into the same main?

On the mac side… Have you tried to install the CHUD tools from the developer software from Apple? (and disable nap in the processor prefpanel you have then installed) see on the OS X install CD/DVD.

[Richard Veenstra]

Hello Macmusic folks. I have a very annoying problem. I am using a g4 powerbook 12" (1.25ghz) with an edirol fa 101 firewire interface and tannoy reveal active monitors. When I plug a external vga monitor into the powerbook, I get a high pitched interference on the tannoys. this also happens if i plug in my printer to usb. i have bought a couple of ferrite core rings from Maplin and tried placing them on monitor and firewire cables, to no avail. Anybody know how to cure this? Mac shop said it may be logic board...
PHEW! THANKS. BRETTY

Hi, I'm experiencing the same problem if I connect my PB G4 to my LCD display using the supplied DVIcable.
I used different USB/FW devices, with the USB device I only notice a hum, with the FW devices also some electromagnetic interference (when you move the mouse, you hear it on the speakers). At the moment, you are the only one I have read which has the same problem. Have you fixed it yet?

I had the same problem using a VGA monitor with the Apple DVI to VGA Adapter. Funny enough, Apple's own Cinema Display is working fine...

I am also using the Tannoy (passive) monitors, but that should be a coincidence...

About the logic board, I have a new logic board installed two months ago and still the same problem, so probably that won't be it.