Sound going in and out at random times on 1 slot

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VRC-SID

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Edited this post instead of creating a new one.

The sound just stops completely, then sometimes comes back on a reset. Its very random where the sound starts / stops. It will sometimes play the SNK song, then play the intro music to the game, but not have any sound after. Other times the SNK song will freeze holding a note for a bit. Kinda odd.

Original post

My 2 slot works great but I got a single slot today and wanted to test it. Plugged it in and got a Z80 Error. While I believe the MVS cable is unrelated to the issue, I know I do not have -5 volts hooked up. Could this cause any issues?
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channelmaniac

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There's one version - I think MV1C? Don't recall - that gives that message if you boot it without a cart in.

MVS boards do not need/use -5v.

If you have a cart in it, try it without. If you still get the error your board needs serviced.
 
Pas

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channelmaniac said:
There's one version - I think MV1C? Don't recall - that gives that message if you boot it without a cart in.

MVS boards do not need/use -5v.

If you have a cart in it, try it without. If you still get the error your board needs serviced.
Click to expand...

You are correct...the MV1C does not have a seperate Z80 (its combined internal to a custom chip) so it posts an error if no cartridge is inserted.
 
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Its a MV-1F. I get a Z80 with or without a cart. Trying to hunt down the source of the problem.
 
channelmaniac

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Most likely a bad Z80 chip.

SNK had a NASTY habit of using Z80 instead of Z80A CPUs. (The Z80A is rated for higher speeds than the Z80) Penny pinching (*#$&(#*@
 
channelmaniac

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Z80, Z80A, Z80B, Z80C, etc... are all the same part. They are rated for different speeds and may be constructed slightly different inside to reach those speeds.

The big difference is that the Z80 is very overclockable but at the cost of higher heat generation inside the chip which leads to failure.

Now with that said, Z8 is not the same as a Z80.

RJ
 
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VRC-SID

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Wish I could yank a Z80 from a NES, Gameboy, etc just to fix it. Is there a place to get this sucker fixed?
 
discgolfer72

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i have a bad ataxx board here with 2 z80's in it if ya need em

ps contact the guy above your last post for repair lol
 
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discgolfer72 said:
i have a bad ataxx board here with 2 z80's in it if ya need em

ps contact the guy above your last post for repair lol
Click to expand...

Whatcha want for them? I would love to get this board up and running again.

PS, contacted the "guy above my post". Thanks for the heads up.
 
discgolfer72

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just pay shipping (wont be much )
channelmaniac was going to burn me some roms for the ataxx board but i ended up getting 3 more working boards so no more need
 
madman

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VRC-SID said:
Wish I could yank a Z80 from a NES, Gameboy, etc just to fix it. Is there a place to get this sucker fixed?
Click to expand...
Gameboy doesn't exactly use a Z80, pinout is totally different in any case. The NES doesn't use a Z80 at all. You should easily be able to find a replacement online for cheap.
 
discgolfer72

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you will have to check with channelmaniac first i think the z80's in the ataxx are 80B so if they are compatible ill just send them to you pm me your info
should not be to hard of a replacement
 
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madman said:
Gameboy doesn't exactly use a Z80, pinout is totally different in any case. The NES doesn't use a Z80 at all. You should easily be able to find a replacement online for cheap.
Click to expand...

:p meant to say Sega Genesis. Brain fried today.
 
channelmaniac

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The Z80B and Z80 are the same CPU. The A, B, C ratings on them are speed ratings.

Z80 are the slowest CPUs. Z80A is rated faster. The Z80B is rated even faster than the A.

Bottom line: The Z80B will work fine in place of the Z80 or Z80A CPUs.
 
V

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I resoldered the pins on the ram, z80, and the yamaha chip. Now it boots sometimes, but the graphics are a tad shaky. They are not glitched, but if feels like parts of the image shifts back and forth by a pixel a bit. Wonder if my RGB to VGA adapter is confused. Although it works with my 2 slot just fine. The very top of the image is skewed a tad too but my 2 slot did that with the converter at first too.
 
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The thing boots 100% of the time now, but the image is still slightly shaky. Wonder if it needs its CAPs replaced. Channelmaniac, got any cap kits for the 1 Slot MV1F? I'm going to try it in a JAMMA cab without an RGB adapter to see if it helps.
 
channelmaniac

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Cap kits are only for audio issues.

I suspect you are having problems with encoder compatibility.
 
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channelmaniac said:
Cap kits are only for audio issues.

I suspect you are having problems with encoder compatibility.
Click to expand...

I popped it into the JAMMA cab and the flickering went away but I get some horizontal distortion on the top 3-4 lines of resolution. Also, the audio is messed up now. The intro Neo Geo song will often pause or stop in the middle. Sometimes the game will play some sounds or music, but its not 100%. Cleaned the connector and cart which helped some. Did get 1 z80 error today, but thats when we put it in the new cab, only happened once.

Now Im trying to fix the audio and the distortion at the top. Getting close though :)
 
discgolfer72

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when you hooked it up to the jamma cab did you make shure to flip the switch from stereo to mono
i bumped my switch when removing a cart (before i wired my cab for stereo) and the sound was crazy (only heard half the tones)

also my mv1ft has the same distortion at the veryy top of the screen (like in kof2003 everything above the life bars is skwed to the right )

but i think this has to do with the monitor adjustment and not the board itself as i get the same problem when i place some of my other jamma boards in the cab(not all of them jsut 2 or 3)
 
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V

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discgolfer72 said:
when you hooked it up to the jamma cab did you make shure to flip the switch from stereo to mono
i bumped my switch when removing a cart (before i wired my cab for stereo) and the sound was crazy (only heard half the tones)

also my mv1ft has the same distortion at the veryy top of the screen (like in kof2003 everything above the life bars is skwed to the right )

but i think this has to do with the monitor adjustment and not the board itself as i get the same problem when i place some of my other jamma boards in the cab(not all of them jsut 2 or 3)
Click to expand...

I'm sure I set it to MONO. The sound just stops completely, then sometimes comes back on a reset. Its very random where the sound starts / stops. It will sometimes play the SNK song, then play the intro music to the game, but not have any sound after. Other times the SNK song will freeze holding a note for a bit. Kinda odd.
 
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