Monitor affecting microphone

[collettnj]

Yesterday I was getting some complaints from a couple of friends on skype that my microphone was making a constant buzzing sound, which had never happened to me before.

I'm using a Toshiba Satellite laptop with onboard (line out/mic)

• When I unplugged the mic, the sound stopped. Plugging in a different mic made no difference, the buzzing was the same.

• Leaving the mic plugged in, but unplugging my headphones made the buzzing MUCH worse. Unplugging both headphones and mic would stop buzzing.

I'm aware that electrical devices can interfere with microphones/speakers etc, so I had a fiddle around today, turning on and off various things (router, other PC etc) in the room to troubleshoot. I've narrowed down the issue to my montor, since turning it off stops the buzzing.

In a quick examination of the monitor, I can smell something quite distinct towards the top of it which I've never noticed before. My best guess is that something has burned up in there. It doesnt feel any hotter than usual however, and the screen works fine; no distortions of any kind.

The monitor is a ViewSonic 19" LCD Monitor VX922, which is just over 3 years old, so out of warranty i'd imagine.

--

How safe would it be to unscrew the back and have a poke around inside? I'm thinking about capacitors etc..

Without knowing much about electronics beyond A-level physics, would it be a fair guess that some insulation has burned up, allowing electrical interference to mess with my sound? If that's the case, is there anything realistic I can do to make it safe/practical to use again?

Cheers!

[arthurleung]

Plastics smells if they're hot. I don't think there should be any problem with it. My monitors and laptops and even harddrives all smells at 60'C+

What I suspect is your monitor power supply produce ripples which propagate to your computer psu, which propagate to your motherboard, where the sound chip is.

Get a cheap soundcard that fits in your PCI or PCIe slot should fix the problem.

Or alternatively tell your friend to reduce the volume on his end, and increase the microphone volume on your end (or speak louder). That should reduce the "noise".

[collettnj]

I'm using a laptop, so an internal soundcard is no option for me, since i have NO idea about the inner workings of laptops! I just have the monitor plugged into the DVI port on my laptop.

As for adjusting my mic volume, I tried that, but increasing the volume just lead to an increase in the buzzing sound for him. Clearly the opposite was true, but then I was too quiet for him to hear.

I'm just curious as to why it'd just start all of a sudden. I haven't moved the laptop or monitor recently, and havent introduced any new electrical equipment to the room. About the smell, on the same day that the problem started, I noticed a weird smell in my room that i'd never smelled before. The smell and the mic buzzing both started within about a 4 hour time window from whatg i can remember, and the smell was definitely the same smell coming out the top of my monitor now.

There must be a link there given that ive never noticed the smell before, nor the mic acting up. How safe would it be to take the back off the monitor?

[arthurleung]

I'm using a laptop, so an internal soundcard is no option for me, since i have NO idea about the inner workings of laptops! I just have the monitor plugged into the DVI port on my laptop.

As for adjusting my mic volume, I tried that, but increasing the volume just lead to an increase in the buzzing sound for him. Clearly the opposite was true, but then I was too quiet for him to hear.

I'm just curious as to why it'd just start all of a sudden. I haven't moved the laptop or monitor recently, and havent introduced any new electrical equipment to the room. About the smell, on the same day that the problem started, I noticed a weird smell in my room that i'd never smelled before. The smell and the mic buzzing both started within about a 4 hour time window from whatg i can remember, and the smell was definitely the same smell coming out the top of my monitor now.

There must be a link there given that ive never noticed the smell before, nor the mic acting up. How safe would it be to take the back off the monitor?

Tried running the laptop on battery power and see if that helps?

[peterb]

Try Arthurleungs suggestion, but it sounds (sorry - no pun intended) as if the inverter that powers the minitor backlight may have developed a problem - possibly a capacitor failing so the inverter is generating more electical noise.

Check that the monitor really is out of warranty before you start opening it up, and if you have no experience of electronics then think twice about doing so. However if you do open it up, you may find a cct board with wires (at least 2 pairs - possibly 4) which go to the backlights. That is the inverter board. Look for any scorch marks on components, or capacitors with bulges on them. If you can identify those, AND you know what you are doing, you can replace the faulty part, otherwise contact Viewsonic and see if they will sell you a replacement inverter.

Alternatively, Google for monitor repair services, but it might be cheaper to replace the whole thing.