xiao_haozi
Avid Neo-Expert
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Yeah, me too. Thanks for the link to that 1A writeup you did. I forgot about that one and re-bookmarked that today. Brilliant sir, brilliant!
MV-1fz Stereo mod problems
- Thread starter Finch
- Start date
Avid Neo-Expert
Yeah, me too. Thanks for the link to that 1A writeup you did. I forgot about that one and re-bookmarked that today. Brilliant sir, brilliant!
- Joined
- Jul 14, 2009
- Posts
- 431
I may do both actually.
This is a lot of fun so I doubt it will be my last arcade related project, maybe I'll do a supergun or something and one of those PSU's would be great, I guess that's what everyone else used them for.
MKL, I'd love to see how to do it, and in the long run 5v only is just more convenient, so count me in on looking forward to the guide.
This is a lot of fun so I doubt it will be my last arcade related project, maybe I'll do a supergun or something and one of those PSU's would be great, I guess that's what everyone else used them for.
MKL, I'd love to see how to do it, and in the long run 5v only is just more convenient, so count me in on looking forward to the guide.
- Joined
- Mar 8, 2002
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- 3,686
Desolder the four components highlighted in yellow (two 4.7uF electrolytic capacitors and two 1Mohm resistors):
Bin the capacitors and keep the resistors:
With a sharp blade (Stanley knife) cut a segment of the trace:
With the smallest flathead screwdriver you can find (jeweler type) scrape off the solder mask on the trace in that exact point until you have a solid copper area. Bend the pin of the chip nearby towards the copper area:
Tin the copper area and the pin so that they're bridged together:
Snip the legs of a resistor (not one of those you desoldered earlier) and bend them into a U shape:
Put them into the through holes where the capacitors previously were and solder them. Trim the legs on the other side:
Take the 1Mohm resistors and straighten them. The legs are coated so you need to scrape the coating off:
Solder the resistors as shown below. The common point is ground. Pre-tin it or it will be difficult to solder to it (it's a point that requires more heat than other through holes):
The MV1FZ has a LED that uses +12V for the anode and +5V for the cathode but due to the solder bridge we made before, the anode now is +5V also, so we need to do something if we want the LED to light up again. Desolder the LED and the 1K resistor R43:
If you want you can use the old LED but it's so ugly and small you may want to use a new one. Put it back reversed with respect to the symbol on the PCB: anode (longer lead) to cathode and cathode to anode:
Solder a resistor (270ohm in my case) across the cathode and one of the ground pins of the DIP switch bank nearby (they're all grounds so any will do):
Now you can do the stereo mod and get sound with a 5V PSU.
Bin the capacitors and keep the resistors:
With a sharp blade (Stanley knife) cut a segment of the trace:
With the smallest flathead screwdriver you can find (jeweler type) scrape off the solder mask on the trace in that exact point until you have a solid copper area. Bend the pin of the chip nearby towards the copper area:
Tin the copper area and the pin so that they're bridged together:
Snip the legs of a resistor (not one of those you desoldered earlier) and bend them into a U shape:
Put them into the through holes where the capacitors previously were and solder them. Trim the legs on the other side:
Take the 1Mohm resistors and straighten them. The legs are coated so you need to scrape the coating off:
Solder the resistors as shown below. The common point is ground. Pre-tin it or it will be difficult to solder to it (it's a point that requires more heat than other through holes):
The MV1FZ has a LED that uses +12V for the anode and +5V for the cathode but due to the solder bridge we made before, the anode now is +5V also, so we need to do something if we want the LED to light up again. Desolder the LED and the 1K resistor R43:
If you want you can use the old LED but it's so ugly and small you may want to use a new one. Put it back reversed with respect to the symbol on the PCB: anode (longer lead) to cathode and cathode to anode:
Solder a resistor (270ohm in my case) across the cathode and one of the ground pins of the DIP switch bank nearby (they're all grounds so any will do):
Now you can do the stereo mod and get sound with a 5V PSU.
L
lilmul123
Guest
Hello, hate to bump an older thread, but I was looking for something about this mod on Google, and came across this thread.
If the MV1FZ board is running off of 12V, then the originally described method should work, correct? If so, is it possible to send the left and right signals directly to speakers instead of RCA jacks? I want to do this mod for my cabinet instead of a consolization.
If the MV1FZ board is running off of 12V, then the originally described method should work, correct? If so, is it possible to send the left and right signals directly to speakers instead of RCA jacks? I want to do this mod for my cabinet instead of a consolization.
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- Jul 14, 2009
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ok, someone else might be able to answer this better than I, but here goes.
The original method (www.neobitz.com 1fz stereo mod) bypasses the onboard amplifier. The onboard amplifier uses 12v but so do some other sound related components that handle sound before it gets to the amp. The original mod gets you stereo sound thats un-amplified, like you would want for a consolized MVS board but it still requires 12v. The 5v mod powers the sound components that still need 12v in the original mod with 5v instead. I'm far from understanding why all that works but it does.
Anyways, if you want the board to run the speakers in your cabinet I think you need to still use 12v and not do either mod. If the original stereo mod bypasses the amp then there won't be enough power in the lines to run the speakers. I may be wrong about this, hopefully someone can step in and clarify.
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- Mar 8, 2002
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- 3,686
No, that method won't work. You need to set the power amplifier to stereo since it's set to mono on the MV1FZ. This require a few alterations like removing and replacing a few components, including the volume pot.
As a result of this mod, the audio pins on the edge connector of this board will be like those of a multi slot, which means it won't work in a Jamma cab unless you do something like adding a Jamma/MVS (mono/stereo) switch.
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