Author Topic: Most common cause of no ADPCM on the Duo?  (Read 640 times)

thesteve

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Re: Most common cause of no ADPCM on the Duo?
« Reply #15 on: May 27, 2012, 08:30:38 AM »
unfortunately i havent been able to get a confirmed pinout for the 5205.
in stock http://store.americanmicrosemiconductor.com/msm5205rs.html

thesteve

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Re: Most common cause of no ADPCM on the Duo?
« Reply #16 on: May 27, 2012, 08:37:54 AM »
http://www.datasheets.org.uk/indexdl/Scans-002/Scans-0053070.pdf
has somewhat better data (could be interchangeable)

ApolloBoy

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Re: Most common cause of no ADPCM on the Duo?
« Reply #17 on: May 27, 2012, 08:39:58 AM »
So what could be causing the voltage problem I'm having? I'm beginning to think the chip is still alive, it's just being undervolted somehow and hence why it doesn't work.
Quote from: Arkhan
it makes me laugh because people are like I REMEMBER PLAYIN THAT BACK IN THE DAY, MAN THAT WAS FUN.

and then I go "yeah I remember playing that 2 days ago because I still have my SNES, retard"

ApolloBoy

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Re: Most common cause of no ADPCM on the Duo?
« Reply #18 on: May 29, 2012, 04:54:57 PM »
No ideas?
Quote from: Arkhan
it makes me laugh because people are like I REMEMBER PLAYIN THAT BACK IN THE DAY, MAN THAT WAS FUN.

and then I go "yeah I remember playing that 2 days ago because I still have my SNES, retard"

thesteve

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Re: Most common cause of no ADPCM on the Duo?
« Reply #19 on: May 29, 2012, 05:18:51 PM »
trace it back
should it be 5V or 8V?
8V regulator is a common issue.
the amps are 8V, so you can check at them

ApolloBoy

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Re: Most common cause of no ADPCM on the Duo?
« Reply #20 on: May 30, 2012, 06:49:09 PM »
Both the op amps under the board and the one near the AV port checked OK and put out 8V as they should. The surface mount caps on the voltage line for the M5205 check out as well. I'm utterly confused as to why this isn't working...
« Last Edit: May 30, 2012, 06:51:37 PM by ApolloBoy »
Quote from: Arkhan
it makes me laugh because people are like I REMEMBER PLAYIN THAT BACK IN THE DAY, MAN THAT WAS FUN.

and then I go "yeah I remember playing that 2 days ago because I still have my SNES, retard"

Keith Courage

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Re: Most common cause of no ADPCM on the Duo?
« Reply #21 on: May 30, 2012, 07:21:29 PM »
I say try changing the chip so you can at least rule that out. I have some spares that I mail ordered(sold out now). I'd be happy to sell you one for what I paid. Just PM me if you want one.
« Last Edit: May 30, 2012, 08:03:41 PM by Keith Courage »

ApolloBoy

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Re: Most common cause of no ADPCM on the Duo?
« Reply #22 on: June 25, 2012, 05:34:14 PM »
Managed to get a PCM chip from Keith and it turned out to be the culprit after all. Thanks to everyone for their suggestions!
Quote from: Arkhan
it makes me laugh because people are like I REMEMBER PLAYIN THAT BACK IN THE DAY, MAN THAT WAS FUN.

and then I go "yeah I remember playing that 2 days ago because I still have my SNES, retard"

thesteve

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Re: Most common cause of no ADPCM on the Duo?
« Reply #23 on: June 25, 2012, 05:57:46 PM »
you found the easter bunny

ApolloBoy

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Re: Most common cause of no ADPCM on the Duo?
« Reply #24 on: June 25, 2012, 06:58:20 PM »
you found the easter bunny
I did indeed. Now if I can just get the laser calibrated right...
Quote from: Arkhan
it makes me laugh because people are like I REMEMBER PLAYIN THAT BACK IN THE DAY, MAN THAT WAS FUN.

and then I go "yeah I remember playing that 2 days ago because I still have my SNES, retard"

turbokon

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Re: Most common cause of no ADPCM on the Duo?
« Reply #25 on: August 05, 2012, 09:13:32 AM »
I got a duo here where I just replaced all the caps. I'm getting audio tracks from the cd where before I didn't but the voices and sound effects are low. Could this be the same thing?
Turbo fan since 1991 after owning my first system.

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www.tg16pcemods.com

thesteve

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Re: Most common cause of no ADPCM on the Duo?
« Reply #26 on: August 05, 2012, 09:28:59 AM »
most sound effects are chiptunes (huCard sound)
the bonk voice in the 3 in 1 demo disk is ADPCM

turbokon

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Re: Most common cause of no ADPCM on the Duo?
« Reply #27 on: August 05, 2012, 09:55:44 AM »
Was playing lords of thunder when I was noticing the low voices and sound effects. So I need to loock around the Adpcm chip?
Turbo fan since 1991 after owning my first system.

Check out my website:)
www.tg16pcemods.com

thesteve

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Re: Most common cause of no ADPCM on the Duo?
« Reply #28 on: August 05, 2012, 10:01:13 AM »
check around the mixer circuit

turbokon

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Re: Most common cause of no ADPCM on the Duo?
« Reply #29 on: August 05, 2012, 12:38:32 PM »
Found a bad trace at C653.  Thanks.
Turbo fan since 1991 after owning my first system.

Check out my website:)
www.tg16pcemods.com