New Famiclone , weird sound problem

Hello guys , im need your help . Recently i bough nintendo famiclone called Hamy HM-8 Ntsc famiclone . But the problem i notice is very strange abnormal sound .

http://vocaroo.com/i/s0w2B4sjgOqD http://vocaroo.com/i/s1fNWvalUaUi
Here is the sound i recorded . I hope you guys have an idea how to slove that issue

 

Is this a NOAC (Nintendo On a Chip) famiclone? Sounds like it has the reversed duty cycles sound problem. If that's the case there isn't much that you can do, sadly.

 

Yes its NOAC famiclone , but i also had alot NOAC famiclones but never face that kind of problem in them

 

If you think the problem is other than the one described above, you can always trace the audio signal to see if something is missing or if there is a bad connection somewhere. In Noacs everything is usually very straight forward.

Got any pics?

 

I really dont understand on these boards where to touch for the sound change and which part controll the sound . So its not like the sound completely missing . In this case is just crazy , like you hear on the record

 

If you have a multimeter do a continuity check and trace the audio signal directly from the Mono RCA jack (white connector) into the gray ribbon cable and then into the board. If it goes directly into the NOAC gloptop then you are out luck. I do see an additional chip near the crystal, I can't quite tell what is it (could be some sort of hex inverter or an op amp). The sound could potentially be coming out of this.

You may want to clean the board a bit with some rubbing alcohol, lots of cheap flux everywhere

This is also a fairly new famiclone (based on the board year label of 2013) seems like they just keep getting worst with time .

 

As i saw video reviews of famiclones familiar to mine ( there is Fc Cube 88 , Fc Tech ) they re the same , even inside the plates but didnt saw that kind of problems in them while watchin the video and sound was ok too

 

Just because the board layout looks the same it doesn't mean it has the same NOAC after all, the actual chip is in the globtop. Your best bet is to trace the audio.

 

On which you called globtop ?

 

The NOAC is the big black globtop located in the solder side of the board near the cart connector. Let me ask you this, do you see that metal looking can part on the board (xtal) ? can you tell me is there is a number stamped on it? if so, what number is it?
I've seen famiclone makers do crazy things

 

21.4772 is the number on the xtal

 

That's the correct part for NTSC.

I once had retro duo (SNES/FC clone) where they installed the wrong xtal and was giving me distorted sound but that's not the case here.

 

Yes the sound speed is for ntsc ( if it was pal would sound slower ) you can hear on the audio records its proper speed for ntsc . The case is different thats worried me