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Hardware > Whazup? My GBA hums.

#118493 - 3yE - Tue Feb 13, 2007 11:22 pm

Hello.

I just got myself my first GBA, and my first handheld colsole at all for that matter. The one i picked up was a used old-style Gameboy Advance (not SP or Micro), since i am not going to use it regularly and would spoil Li-Ion battery very soon. Besides, i just happen to like AA rechargeables.

How, the question i have. The headphone output hums at low frequencies. The humming does not depend on the volume setting. I believe it depends on the headphone impedance: it is almost not noticable with 45 Ohm headphones and quite a nuisance with 16 Ohm earphones, though i would have to do more tests to conirm that. The hum definately depends on the display contents: black-only screens make it disappear, and it seems to me, white also does.

So, does anyone have a clue what's wrong or where to trace the problem? I'm somewhat under the impression that it got nearly flushed down the toilet once, since all the internals were soled with some brownish mass. I have taken the board out and put it into spiritus for a few minutes, so it seems clean now.

My second consern would be adding some sort of screenlight, perhaps other mods. Can you recommend me any sources of information?

#118496 - tepples - Tue Feb 13, 2007 11:32 pm

It's probably a signal leak from the LCD driver to the audio amp. A lot of systems do that.
_________________
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-- Who?
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#118507 - HyperHacker - Wed Feb 14, 2007 12:26 am

When I wear headphones with my DS, and don't have music playing, I can tell just what it's doing from the sound it makes. Different pitches depending on the contents of the screen. It's kinda neat (and since it goes away when the screens are off, it's not a big deal).
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I'm a PSP hacker now, but I still <3 DS.

#118937 - NeX - Sun Feb 18, 2007 11:00 am

Mine hums if you turn all the sound down and put your ear to the battery compartment. It's really high frequency - hard to hear as you get older.

#119020 - HyperHacker - Mon Feb 19, 2007 3:47 am

Hm, I noticed with my headphones I can hear a pop when I plug them into my DS, even when it's turned off. O_o
_________________
I'm a PSP hacker now, but I still <3 DS.

#119055 - keldon - Mon Feb 19, 2007 11:29 am

HyperHacker wrote:
Hm, I noticed with my headphones I can hear a pop when I plug them into my DS, even when it's turned off. O_o


That happens when you plug anything into an electrical circuit! Some devices choose to control this with [possibly] gates/reed relay circuits.

Humming could be down to grounding problems caused by the wetting of the system. Higher impedance means more resistance, therefore reducing volume.