I game sound problem

[smileman83]

Hello agin- I am having trouble diagnosing a sound issue on an I game plus I am repairing. I am a bit of a newbie but have been having fun learning. The machine works well, but when turned on, there is a pop sound from the speakers, and only the right speaker works ( and the subwoofer) , but the left speaker doesnt work. After you play for about 5 minutes, the left speaker will come on. Then after another 10-15 minutes, the pop sounds and the left speaker cuts off. I am unfamiliar with the connection of sound simm, to amplifier, to the small upper board where the speaker outputs come from, but any direction would be great.

Thanks to all in advance.

Bruce

[Tilt]

Most likely bad caps on your multimedia lite (MML) board.  That's the daughterboard that is mounted to your MPU board and the sound simm plugs into.  It's easier to just replace the MML then trying to repair it though unless you have experience replacing surface mount components.

[smileman83]

Okay I have another MM lite- Ill try taht first- I didnt know what the path of sound was- MMlite, through an amp of sorts to the speakers?? There is also the sound board in the upper cabinet where the speakers come from. This also has caps on it- do these also go bad? I am not sure what the board is called.

[Tilt]

I'd be surprised if that didn't fix it.  The board in the upper cabinet is an audio amplifier.  I'm sure they can fail, but popping sounds, intermittent static, and other general audio mayhem is usually due to a bad MMLII board.

[smileman83]

That was the issue Tilt. Appreciate it. I assume the old board is trash- no reason to save?

[Tilt]

Good deal.  Yeah, unless you have the tools and skills to solder surface mount components you might as well chuck it in the trash.    for the followup post, it may help someone else down the line.

[smileman83]

I do solder all the time, but this board doesnt have the usual caps that I used to seeing so unless its a known issue as to which cap is bad, Ill scrap.

[Tilt]

In that case remove C57 & C59 and see if it resolves your problem.  They are square brownish colored surface mount caps on the end of the MMLII board.  These two are used for the auxiliary audio input that's isn't used unless you plug an audio source into the jack (J3) at the other end of the board.  You don't need to replace them unless you ever plan on using that input.

[smileman83]

So i am a little unclear- if they arent used, why would i replace those particular caps- do you think they still are the root of the problem?

[Tilt]

You don't have to replace them, just remove them. They are optional unless you use the aux audio input.   I've had two boards where one of these two caps was bad and caused loud pops and loss of audio in one channel.  If removing those two doesn't resolve it, then most likely replacing C33 & C34 will.  So try removing them, then test board.  If pops are gone, great!  If not, remove C33 & C34 and replace them with the caps your removed from C57 & C59.  Test again, if it works you're done.  If not, trash it.