macklin01
02-26-04, 09:17 AM
I'm putting this in general hardware because I believe it's more of an electrical issue than a display issue.
Here's the basic symptom: When my LCD receives a video signal, it emits a high-pitched hum.
Here's the equipment:
1) Sparkle 350W PSU, Abit AI7, P4 3.0C, Abit Siluro Ti4200 (128MB), WD800JB, 512BM PC3500, Samsung CDRW/DVD combo drive, some smallish case fans, Creative SBlive! 5.1, floppy drive.
2) Samsung 151v 15" LCD flat panel monitor
3) Altec Lansing 2.1 speaker system, joystick, cable modem, bubble jet printer, D-Link wireless router / firewall
4) 700VA ups connected via serial port
The items from (1)-(2) are connected to the powered outlets on my UPS. Those in (3) are connected to a powerstrip on an unpowered outlet.
I have done some testing to eliminate possibilities:
1) I disconnected everything from the UPS except for the computer and LCD. I still get the hum. So, it's no interference from any of the items in (3).
2) I unplugged the UPS and powered just (1)-(2) from a power strip directly, and I still get the hum. So, it's not caused by the UPS.
3) I tried connecting the LCD to the DVI-out of the video card, with no change. So, it's not the VGA-out of the video card.
4) I disconnected the video cable from the computer (so that "no-signal" showed on the LCD. I still got the hum. So, it's not the video card.
5) I unplugged the monitor and plugged it in elsewhere. The hum disappeared. So, it's not the monitor in and of itself.
6) I plugged the monitor back into the UPS and turned off the computer. I unplugged the video cable to get "no-signal". There was no hum until I turned on the computer.
So somehow, it has to do with the computer being powered on the same circuit as the LCD. As far as I remember, this did not occur with my previous 300W TTGI PSU and PIII-S system.
Now that I listen to the LCD and it's been running for awhile, I see that the hum has disappeared, so it may be intermittent.
Does anybody have similar experiences to this and ideas on how to reduce or eliminate it?
Thanks! -- Paul
Here's the basic symptom: When my LCD receives a video signal, it emits a high-pitched hum.
Here's the equipment:
1) Sparkle 350W PSU, Abit AI7, P4 3.0C, Abit Siluro Ti4200 (128MB), WD800JB, 512BM PC3500, Samsung CDRW/DVD combo drive, some smallish case fans, Creative SBlive! 5.1, floppy drive.
2) Samsung 151v 15" LCD flat panel monitor
3) Altec Lansing 2.1 speaker system, joystick, cable modem, bubble jet printer, D-Link wireless router / firewall
4) 700VA ups connected via serial port
The items from (1)-(2) are connected to the powered outlets on my UPS. Those in (3) are connected to a powerstrip on an unpowered outlet.
I have done some testing to eliminate possibilities:
1) I disconnected everything from the UPS except for the computer and LCD. I still get the hum. So, it's no interference from any of the items in (3).
2) I unplugged the UPS and powered just (1)-(2) from a power strip directly, and I still get the hum. So, it's not caused by the UPS.
3) I tried connecting the LCD to the DVI-out of the video card, with no change. So, it's not the VGA-out of the video card.
4) I disconnected the video cable from the computer (so that "no-signal" showed on the LCD. I still got the hum. So, it's not the video card.
5) I unplugged the monitor and plugged it in elsewhere. The hum disappeared. So, it's not the monitor in and of itself.
6) I plugged the monitor back into the UPS and turned off the computer. I unplugged the video cable to get "no-signal". There was no hum until I turned on the computer.
So somehow, it has to do with the computer being powered on the same circuit as the LCD. As far as I remember, this did not occur with my previous 300W TTGI PSU and PIII-S system.
Now that I listen to the LCD and it's been running for awhile, I see that the hum has disappeared, so it may be intermittent.
Does anybody have similar experiences to this and ideas on how to reduce or eliminate it?
Thanks! -- Paul