Neo MVS MV-1fz video Problems

dragonpt

Over Top Auto Mechanic
10 Year Member
Joined
Oct 19, 2008
Posts
867
Hi Guys

I'm desperate I just bought on Ebay A MVS model MV-1fz, but i'm having some hard video problems

Plz see this video i made:

_http://www.youtube.com/watch?v=PsC09sYqAMA

Please help me :hammer:

Xeers

(sorry my bad English i'm Portuguese)
 

mainman

CPS2 Person.,
20 Year Member
Joined
Mar 26, 2001
Posts
3,721
I would like to help but I'm at work and you tube is blocked. What are the symptoms.
 

Xian Xi

JammaNationX,
15 Year Member
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Dec 1, 2005
Posts
27,748
That's a sync problem, check if there is any signal on the pin.
 

Murray

Akari's Big Brother
Joined
Aug 16, 2005
Posts
2,533
It looks like the picture is constantly scrolling diagonally from lower-left to upper-right. I'm going to call it a sync problem but outside of that I have no idea how to go about fixing it.
 

dragonpt

Over Top Auto Mechanic
10 Year Member
Joined
Oct 19, 2008
Posts
867
It's sync problem allright !!! :(

I just disconect the "P" pin on the jamma (Sync), and the image is exactly the same

That's not ok, i'm not getting any signal from it

I even test with a wire,from the "P" pin to the scart pin, and the result was the same

Can i get the sync signal, from other location ? :(

Thanks
 

dragonpt

Over Top Auto Mechanic
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Oct 19, 2008
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Check the resistor on the sync line.

I have check both the resistors with a voltemeter (sorry my English), one is 100 ohm and the other 471 ohm, both are ok

I'm going crazy with this

can i get the signal, from other location, or do you know were is the signal coming from, what is the name of the chip?

Thanks
 

MKL

Basara's Blade Keeper
20 Year Member
Joined
Mar 8, 2002
Posts
3,686
On the MV1FZ sync is outputted from pin 150 of GU2 (LSPC2). From there it goes to pin 1,2 of U1 (74LS32) and from pin 3 of U1 to jamma P with 100 ohm resistor in series and 470 ohm resistor to 5v. Lift pin 1,2 of U1 from the PCB and tap sync from the vias just before those pins, after checking continuity with GU2 (150). If the picture keeps rolling either the LSPC2 is faulty or your monitor/TV can't handle the sync signal (50hz only PAL TV??). If the picture syncs OK then it's the LS32 that is faulty.

I watched your video: can you get games to display with carts inserted or is it stuck in hardware test?
 
Last edited:

ttooddddyy

PNG FTW,
Joined
Nov 29, 2001
Posts
8,335
Do other boards work OK ??

As MKL mentioned, possible TV/monitor issue with 50Hz only vertical. (for PAL)
MVS runs at 59.19 Hz. which may be out of range.

Edit-I can not access the youtube clip. Is the horizontal sync locked ?
 
Last edited:

dragonpt

Over Top Auto Mechanic
10 Year Member
Joined
Oct 19, 2008
Posts
867
On the MV1FZ sync is outputted from pin 150 of GU2 (LSPC2). From there it goes to pin 1,2 of U1 (74LS32) and from pin 3 of U1 to jamma P with 100 ohm resistor in series and 470 ohm resistor to 5v. Lift pin 1,2 of U1 from the PCB and tap sync from the vias just before those pins, after checking continuity with GU2 (150). If the picture keeps rolling either the LSPC2 is faulty or your monitor/TV can't handle the sync signal (50hz only PAL TV??). If the picture syncs OK then it's the LS32 that is faulty.

I watched your video: can you get games to display with carts inserted or is it stuck in hardware test?



GOD BLESS YOU :multi_co: :drool:

With your info, i found that there was no continuity, from U1 (74LS32) and pin 150 of GU2, one of the tracks was cut, i solder a very small wire from those 2 points (uffffff that was HARD...) :scratch:

Also put two new caps of 470 uF at 16v, the older ones, were bad

I now have a very good picture

THANK YOU


BUT... The sound is terrible, very low, and with very interferences and some strange Sounds, even with the mobo volume at max, and the tv volume at max, the volume is low, and with some strange sounds

It's life, one problem fixed, a new one just come :conf::eek_2:


Thank you very mutch

YOU SAVE ME FROM GOING (EVEN) MORE INSANE
 
Last edited:

dragonpt

Over Top Auto Mechanic
10 Year Member
Joined
Oct 19, 2008
Posts
867
Do other boards work OK ??

As MKL mentioned, possible TV/monitor issue with 50Hz only vertical. (for PAL)
MVS runs at 59.19 Hz. which may be out of range.

Edit-I can not access the youtube clip. Is the horizontal sync locked ?

My tv, runs both PAL/NTSC, i bought that tv, just for games (imports and so one)

Thanks
 

channelmaniac

Mr Neo Fix-it
15 Year Member
Joined
Nov 29, 2005
Posts
4,275
Sound problems are common on the Neo Geo boards.

Look around the audio amplifier section of the board. Write down the cap values and go pick some up at your local electronics store.

There are enough problems on the Neo that I put together a bunch of cap kits for the boards but I don't have one built for the 1FZ.

RJ
 
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