Screeching Audio on AES

Xian Xi · Jan 8, 2011

Neo jingle is perfectly fine.

Audio has screeching on top of the music. Music and sound effects are present in the background. Also the screeching is on both the AV and headphone jack.

Just wondering if anyone knows the cause before I have to dive in with the probe and stuff.

Kyuusaku · Jan 9, 2011

Broken/shorted trace on the YM2610 buses. The error in the data accumulates (since it's ADPCM) and causes distortion. Check A34-A47 and B32-B47 from CHA connector back to the YM.

channelmaniac · Jan 9, 2011

Bingo!

Clean the slot/cart first... then look for the broken or corroded traces.

A big clue on the trace condition is if you see gunk around the slot from something being spilled on top of the AES.

Xian Xi · Jan 10, 2011

Kyuusaku said:
Broken/shorted trace on the YM2610 buses. The error in the data accumulates (since it's ADPCM) and causes distortion. Check A34-A47 and B32-B47 from CHA connector back to the YM.

I'll check this.

channelmaniac said:
Bingo!

Clean the slot/cart first... then look for the broken or corroded traces.

A big clue on the trace condition is if you see gunk around the slot from something being spilled on top of the AES.

Nah, I ALWAYS clean slots and connectors first before diving in. Z80 and SRAM are functioning normally. So moving to the YM2610 and see what happens.

Xian Xi · Jan 10, 2011

Quick and dirty:

Code:

A34	Z80	34
A35	Z80	35
A36	Z80	36
A37	Z80	37
A38	Z80	38
A39	Z80	39
A40	Z80	40
A41	Z80	1
A42	Z80	2
A43	Z80	3
A44	Z80	4
A45	Z80	5
A46	SRAM	20
A47	LS04	9

Code:

B32	NEO-C0	113
B33	NEO-C0	114
B34	NEO-C0	115
B35	NEO-C0	116
B36	NEO-C0	117
B37	NEO-C0	118
B38	NEO-C0	119
B39	NEO-C0	120
B40	YM2610	2
B41	YM2610	3
B42	YM2610	4
B43	YM2610	5
B44	YM2610	6
B45	YM2610	7
B46	YM2610	8
B47	YM2610	9

Kyuusaku · Jan 10, 2011

Ooops, my bad, I meant the PROG board, the connections should ONLY be to the YM2610 (It's the V ROM buses).

Xian Xi · Jan 10, 2011

LOL, I was wondering why.

I'll check. Also what is the deal with the extra traces on the 1st gen AES that go nowhere?

channelmaniac · Jan 10, 2011

Probably small ground traces to reduce RFI.

Hewitson · Jan 10, 2011

The Commodore 64 could do with a few of those :lolz:

Kyuusaku · Jan 11, 2011

If signals run right off the board they were used for testing.

Xian Xi · Jan 11, 2011

From the prog board:

Code:

A		
		
32	2,6	LS74-P3
33	33	YM2610
34	48	YM2610
35	49	YM2610
36	50	YM2610
37	51	YM2610
38	52	YM2610
39	53	YM2610
40	54	YM2610
41	55	YM2610
42	41	YM2610
43	42	YM2610
44	43	YM2610
45	44	YM2610
46	47	YM2610
47	46	YM2610

Code:

B		

32	17	YM2610
33	16	YM2610
34	15	YM2610
35	14	YM2610
36	13	YM2610
37	12	YM2610
38	11	YM2610
39	10	YM2610
40	23	YM2610
41	22	YM2610
42	35	YM2610
43	36	YM2610
44	37	YM2610
45	38	YM2610
46	NC	
47	21	YM2610

Where is B46 supposed to go?

MKL · Jan 11, 2011

Xian Xi said:
Where is B46 supposed to go?

To YM2610 (20).

Xian Xi · Jan 11, 2011

That was it. Thanks a bunch guys for the help.

Screeching Audio on AES

Xian Xi

JammaNationX,

Kyuusaku

B. Jenet's Firstmate

channelmaniac

Mr Neo Fix-it

Xian Xi

JammaNationX,

Xian Xi

JammaNationX,

Kyuusaku

B. Jenet's Firstmate

Xian Xi

JammaNationX,

channelmaniac

Mr Neo Fix-it

Hewitson

Metal Slug Mechanic

Kyuusaku

B. Jenet's Firstmate

Xian Xi

JammaNationX,

MKL

Basara's Blade Keeper

Xian Xi

JammaNationX,