Static & noise through audio jack

Title says it all. Pretty much brand new Compal PBL21, I put it together myself but it was very straightforward. I can't imagine why this would be happening.

Updated the drivers with no change, I can hear it in BIOS, as soon as it turns on. Its worse when it's plugged in, but it doesn't go away completely on battery. In fact its worse when I push on the dc plug slightly.

So I guess it's not grounded properly but why would that happen? I'll have to open it up again and poke around at the audio board while it's powered on. Anyone have experience with something like this?

 

At what volume level do you hear the static, and how loud us the static? It sounds like a shielding issue, or a cable is running to close to em noise. Check your cable routes, and connections.

 

Well I couldn't tell you how loud it is in decibels but I can definitely hear it. At all volume levels. Even on mute. Though it does get quieter at lower volumes and when muted.

Like I said I tried 2 power adapters but I can still hear it on battery. I just tried a different pair of headphones with no change. I'm gonna take it apart in a few minutes here...

 

Could be a short on your motherboard/audio chip? I've had that happen numerous times.

 

Sure but how would I be able to pinpoint that and do something about it? I haven't looked at the other side of the motherboard yet but I don't think it will do much good.

I'm thinking of wiring the speaker output to the audio jack - it doesn't seem to have the same problem, can't be sure until I try it. If it doesn't I guess I'll try replacing the audio/usb board. Maybe I shouldn't complain, got the laptop barebones for under 100$.

 

Well I wired some headphones to the speaker output - no change. Damn. This means that the problem is in the motherboard itself. I even unplugged the audio board.

At least there are lots of possible workarounds... I have a line 6 kb37 with a USB audio interface, though it's not something I can really carry around with me. Another thing I thought of is to use the HDMI audio output - there are HDMI to VGA adapters on Ebay that include a 3.5mm audio jack. But, do those work? Anyone bought one? I know there are lots of fake adapters on Ebay. This is the one I'm looking at:
HDMI Male to VGA Audio HD Video Cable Converter Adapter 1080p F 3 5 Audio G6 | eBay

I wouldn't mind having a PBL20 motherboard, without the GT 540m, but I'm not sure how I could sell this one for the same price in good faith. Maybe the seller can exchange the motherboard, but maybe they don't have a clue how to take it apart. :/

 

goddammit

 

I think USB headphones or speakers are your best bet. They make usb sound cards as small as flash drives.

 

Yeah, I think I'm gonna exchange the motherboard unless the seller decides to give it to me pretty much for free.

 

Well a new motherboard did not fix anything.

Its related to my SSD. Not nearly as loud with a hard drive. But its still there, I can't believe no one else has had this issue, maybe my ears are more sensitive?

I have some nashua tape, I'm going to attempt to do some shielding soon

 

Does your SSD have a metal case? Either way, you might try wrapping it with aluminum foil. But first wrap it with a insulator so you don't short something on the drive or the motherboard. And also keep an eye on temps, as it will run warmer when wrapped up.

Many people complain of some noise on the headphone jack, depending on the model of notebook, especially when turned all the way up. Most go with usb headphones.

 

Bad idea, especially since you're drawing at straws rather than using any scientific method to isolate the problem. Nevertheless, my biggest concern is your imprecise description of the problems. For one, static covers a wide gamut. A very wide gamut.

Therefore, you should first start by being more precise when describing the when, where, how, how much, and on what occasion the static exist. Is it continuous or does it fluctuates. If it does fluctuate what are you doing when this happens?

Again, what does it sound like? Is it a scratching, crackling, popping, hissing, crumpled foil type, etc.? The more detailed you are, the more likely you will be to get an accurate answer.

For example, right now I have an inexpensive pair of Logitech powered speaks. When I first turn it on there is a crackling static as I rotate the switch from off to on and increase the volume. Once the tone is set and I release the knob, the crackling stops completely.

Therefore, I know the problem is in the switch, not the circuitry. Move the connectors around and listen for any fluctuation of the static. If it truly is in the circuitry, it should not have any effect on the noise. Otherwise you know its post circuitry. and time to take more aggressive measures.

 

Your right. It's not grounded properly. My SGS3 does the same thing when I have the USB charger and 3.5mm jack plugged in at the same time. Slight feedback noise that will increase when I up the volume because the audio jack's ground is not isolated from the input power's DC ground (or so I conjure).

 

For headphones go to the Realtek Audio Manager in Windows Control Panel and change the Analog Back Panel from Headphones to Line Out, this is a remedy for me on my Lenovo Y570 which is known to have static noise through plugged in headphones.

 

why are you *concerned* about how i describe things relax

firstly let me bring to light another (related?) problem: the USB ports on the same daughterboard as the audio jack do not work properly. at least they can't power my line 6 kb37 correctly.... it disconnects and reconnects and it bluescreened at least once after that. the USB port on the left side, mounted on the motherboard, works fine and also happens to be a USB 3.0 port.

OK i'll try to give as much information as possible

• there is no analog switch involved certainly not an analog volume knob
• most of the time its pretty typical sounding digital static? i don't know how to be more specific tbh? white noise and hissing i guess
• it fluctuates depending on CPU or GPU usage i think. during use there are other digital noises, distorted sine wave sweeps when minimizing windows, distorted humming, rhythmic clicks of static etc
• MOST of the background static goes away when it's unplugged and on battery but the noises that come from processing and stuff are still just as loud (and more audible)
• it DOES get louder when i turn the volume up, but is still present when its muted
• the volume changes depending on the colors the LCD is displaying. most noticeably white and very bright colors makes it louder while all the darker colors make it quieter
• LCD brightness control has no effect
• the only time it is NOT audible at all is for a few seconds during windows start up right before it shows the login screen. it's present at POST and BIOS etc
• i was able to wire the speaker output (meaning the wiring for the built in laptop speakers) up to a pair of headphones and the noise is still present, although that output seems to have a timeout period and they turn off after a few seconds of no audio, then there's no noise. the speakers are wired directly to the motherboard.

i'm thinking maybe there is a cable and/or a grounding screw that isn't connected, i might go ahead and poke around in there soon. would it be a bad idea to stick a wire in the ground pin of an extension cord and try touching it to some ground points while running to see if it helps?