Z80 Error- Audio Related?

zed7

n00b
Joined
May 9, 2020
Posts
42
Hello, as of today I've developed a Z80 Error, that I believe to be audio related. Here's the sequence of events:

MVH-MV4, MVS-4-25 rev 3

Audio somewhat quiet since purchase of cabinet ~3 weeks ago and one speaker may be louder than the other.

Today, all audio stopped completely. After all attract screens finish for the games and goes to the Neo Geo intro, it crashes after playing it with a garbled O and G from Neo Geo. After about resetting 3 times it seemingly did a reset after crashing to tell me that it's a Z80 error.

When the audio initially died, I had just put the K7000A chassis back in after a cap kit and the tube to neckboard ground wire had fallen loose, heard a sound similar to arcing from the monitor and noticed the credit counters flickered briefly. When I fixed this the monitor seemed fine, as did the games playability, other than no audio and the crashing.

I had just ordered caps for the audio earlier today before this happened (good timing) and I'm hoping that'll fix the audio problem. If not, what should I narrow in on? the YM2610, or something else in between the YM2610 and Z80, maybe something else? Did I possibly short something?

Apologies if there's another thread I could sift through for the right information, or if this isn't properly formatted with the correct information.

Checked MVS edge connector, F(?, top side of edge connector) has 0v and 6(bottom?) has 12.5v. I can double check tomorrow morning to make sure I'm not incorrect about that.

I have no earth ground currently, working on getting that implemented.

Thank you very much for any help, will update this with extra information I can check tomorrow and if any oddities are fixed.
 

egg_sanwich

Windjammers Wonder
10 Year Member
Joined
Oct 9, 2012
Posts
1,379
Replace the caps first, that’s a good first step.

If you still get z80 error after that, replace z80

Good luck!
 

ack

Ninja Combat Warrior
15 Year Member
Joined
Apr 9, 2009
Posts
538
I would suggest also cleaning your cart edges and cart slots.
 

zed7

n00b
Joined
May 9, 2020
Posts
42
Replace the caps first, that’s a good first step.

If you still get z80 error after that, replace z80

Good luck!

If there's no audio after the cap kit, would I prioritize the YM2610 instead of the Z80? Thank you.

I put the 4 slot into my 2 slot cabinet to see if I got audio, and nothing with the crash still (doesn't always say Z80 error, happened only 1/6 times)

I was even able to play MS X with no issue for a minute, so I've narrowed in on the audio section being the problem, but I could be wrong
 

egg_sanwich

Windjammers Wonder
10 Year Member
Joined
Oct 9, 2012
Posts
1,379
I’d still try replacing the z80, but I guess you could do both if you have the parts on hand.

On my 4 slot I had with no audio and a z80 error, caps and a new z80 fixed it.

In any case see how the cap kit does and go from there. Replacement z80s are cheap enough or you could even salvage one from a parts board or borrow from a working board if you’re impatient.
 

ack

Ninja Combat Warrior
15 Year Member
Joined
Apr 9, 2009
Posts
538
A bad z80 and/or bad YM2610 will not cause games to crash. Before you waste your time swapping chips, clean your cart edges / cart slots. They will oxidize over time causing bad/unstable connections, which will result in random game crashing and sounds issues.
 

zed7

n00b
Joined
May 9, 2020
Posts
42
A bad z80 and/or bad YM2610 will not cause games to crash. Before you waste your time swapping chips, clean your cart edges / cart slots. They will oxidize over time causing bad/unstable connections, which will result in random game crashing and sounds issues.
The games themselves are not crashing, it's the "NEO GEO GIGA POWER" screen after finishing the attract screen of all the games inserted.
 
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