Mv1fz Sync/Display issue

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Spirit0r

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Hallo Gurus,

Today I consolized a MV1FZ, did all the appropriate mods and it works "fine" .

Though i have this issue which i cannot described correctly, the output is displayed halved and twice (Please see image attached).

I am using RGB to scart cable which is working fine with my Mv1fzs.

I suppose i dont have to do any modifications to the cable as long as it works to an almost identical system.

Any thoughts will be greatly appareciate it.

Best regards,
Spirit0r
 

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Neo Alec

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What kind of monitor is it? Is it NTSC?
 
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Spirit0r

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Neo Alec said:
What kind of monitor is it? Is it NTSC?
Click to expand...
Hi Neo,

Thank you for your response!
Its a 8" inch Sony PVM-8044Q.

It is set as PAL, region can be changed via internal trimmer pots. I do get color though.

Best regards,
Spirit0r
 
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Neo Alec

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If you're using RGB from the MVS board without any encoder then it won't work with a PAL display. It needs to be NTSC.
 
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Spirit0r

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Neo Alec said:
If you're using RGB from the MVS board without any encoder then it won't work with a PAL display. It needs to be NTSC.
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Hi Neo!

Thank you for your input! I will look to adjust the monitor for further testing but how it is explained that my other MVS works straight away?

Best regards,
Spirit0r
 
Neo Alec

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What's your other MVS and how is it connected? If you're using it on a PAL display, an arcade board won't work without modification. To start with, PAL displays are 50 Hz, while arcade monitors and NTSC are both 60 Hz, which is my understanding of why you're seeing the image doubled above.
 
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Spirit0r

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Thank you for your responses and your inputs!

From the little reading i did, LSPC2-A2 is responsible for CSYNC and PAL/NTSC selection.

My other MVS is RGB tapped with the same cable, same monitor.

I am not really sure though if it is Sync issue or something else, I want to have a better understanding of the problem before starting butchering things.

For starters i just measured the resistors before the csync pinout and they are fine. Tracking back they connect to a LS32 latch and then to LSPC2-A2. I hope LSPC2-A2 is not the issue.

Best regards,
Spirit0r

​

 
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Spirit0r

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Hi all,

Probed CSYNC with a scope and seems to be fine, 15.63khz stable.

So i believe CSYNC output is not the issue.

Best Regards,
Spirit0r
 
Neo Alec

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What is this RGB to scart cable you mentioned?
 
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Spirit0r

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Neo Alec said:
What is this RGB to scart cable you mentioned?
Click to expand...
Excuse me for the confusion.

It is just a RGB tapped to DIN socket and from DIN socket to scart male , no other active compoments ike sync strippers or encoder.

Then I connect this cable to a female scart to BNC cable that connects to PVM monitor.

The only difference from the image attached is that i added 75ohm resistor + 220uf capacitor in series with every color line.
And ofcourse the composite mentioned in picture is CSYNC without any resistor added.

Its a really peculiar issue, its like the resolution is not set correctly.

Best Regards,
Spirit0r
 

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Neo Alec

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Spirit0r said:
Excuse me for the confusion.

It is just a RGB tapped to DIN socket and from DIN socket to scart male , no other active compoments ike sync strippers or encoder.

Then I connect this cable to a female scart to BNC cable that connects to PVM monitor.

The only difference from the image attached is that i added 75ohm resistor + 220uf capacitor in series with every color line.
And ofcourse the composite mentioned in picture is CSYNC without any resistor added.

Its a really peculiar issue, its like the resolution is not set correctly.

Best Regards,
Spirit0r
Click to expand...
Okay, thanks for the clarification. So these are both a simple consolization (CMVS) with a DIN jack for RGB output. As is, they should only work with an NTSC display. They should not work on a PAL.

I don't think the pin on LSPC2-A2 you mentioned is enough. I've never heard of anyone doing a PAL modification this way. I would expect the crystal oscillator would need to be replaced as well.
 
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Spirit0r

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Hi Neo!

I will not question, ofcourse, your knoweldege with such experience. I am totally new to this hobby!

But for the proof of concept please see attached my other CMVS Mv1fzs with the same setup.

I observed the crystals in both boards and they are identical.

Also in LSPC2-A2 pinout i observed that pin64 is for PAL/NTSC selection but i dont know how to trigger between the modes. Wiki says it is latched on boot.

Also read in the forum that MV1FZ boards are picky with sync and it is recommended to put an 1k pot in CSYNC line in order to adjust the resistance and find the correct value. This will be my next test.

Thank you everyone for helping me out!

Best regards,

Spirit0r
 

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Neo Alec

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Yeah. So I think probably what's happening is that your pro monitor is handling the NTSC style signal just fine, but the problem is the sync signals on your two MVS boards aren't the same. I've found the sync and the strength of the RGB signals can vary a lot, even between different MVS boards of the same model. TTL sync itself can officially vary between 2.4-5v so that already tells you there can be a lot of variation even within official specs.

You can try wiring a pot to the sync line and see if that helps. I wouldn't turn it too high, since you're dealing with TTL sync coming off the board, which can potentially damage equipment if too strong. It's possible you've got a board that simply isn't going to cooperate with certain monitors -- I already have at least one MVS board that will not display an image on certain devices. The sync signal on NGCD systems, for example, (sync on composite or otherwise) is famously terrible, and can cause a lot of compatibility issues.
 
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Spirit0r

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Thank you very much for your insights Neo!

I did put a trimmer pot and unfortunately didn't make any difference.

I am at the process of recaping right now as last resort and if there is no success i will put the board aside as i dont know what else to do.

Best regards,
Spirit0r
 
Neo Alec

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Yeah, next step would probably be to try a different display.
 
DaisyAge

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A bit late to the party here, you could try the DFO mod to get rock solid 50 or 60hz from the board. Just my two cents though, the MV1FZ/S are notoriously shit compared to most other revisions. I would know, I've had like 4 :ROFLMAO:
 
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