Bad Luck with my MV-1FZ Mainboards

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Dear Members.. This is my first post. My Name is Patrick and I am from Austria. I always wanted to have a Neo Geo and finally my dream will soon come true.

I ordered 3x Mainboards from different places around the Interweb. All of them are MV-1FZs.

However when firing them up for the first time all of them had a Garbage Screen.. One had a Video Ram Error Message which then later became a similar Garbage Screen.

What I tried:
Resolder the chips (RAM, NEO, etc.)
Cleaning of the PCB with IPA
Testing another power supply
Pressing on parts while running to see if something changes (nope)
Check for broken traces with a loupe


So far I could not find the cause for this. On one board I found that the fast VRAM (upper) got a little bit hot when plugged in, all the other chips stay cool.
So I guess I will have to try to replace those - can those chips produce garbage screens and are they broken often ? How likely is it that all of my mainboards have a similar issue ? Most errors I read on the forums at least drop some kind of Error Message (which would be a lot easier to work with).

I will add more pics later when I am back home (some mainboard have more of a green garbage screen while others tend to be more reddish)

Any help or comments greatly appreciated

Thanks guys :buttrock:
 

Attachments

  • received_1000219596826542.jpeg
    received_1000219596826542.jpeg
    510 KB · Views: 129

GadgetUK

Ace Ghost Pilot
Joined
Sep 27, 2013
Posts
1,323
Burn SMK Dans diagnostic BIOS and test with that! You may just find some RAM faults on there.
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Burn SMK Dans diagnostic BIOS and test with that! You may just find some RAM faults on there.

Hey :)

I will have to wait for my EPROMs to arrive and will do that then. Are there different Diagnostic versions available ? If so which one do you recommend ?

Also I am very well aware about your videos - As I watched them all in the last few weeks and I loved them.
However without no Error Message and no Sign of Life and the lack of Spareparts (for now) it is hard for me to point the finger on which part could cause this behavior. Here are some more pics of one of my problem boards.

With 2 of my 3 bioschips I will get only the green pattern garbage.. one of the bios chips however creates a more colorful garbage with the watchdog clicking.

I have unsoldered all the parts from one board which also did not work so I could just try replacing all parts like wild and hope for the best - I guess :(

greets, patrick
 

Attachments

  • 1t.JPG
    1t.JPG
    130.6 KB · Views: 124
  • 2t.JPG
    2t.JPG
    227.2 KB · Views: 126
  • 3t.JPG
    3t.JPG
    154.5 KB · Views: 122
Last edited:

Dropwire

Kuroko's Training Dummy
Joined
Jul 27, 2018
Posts
75
There is one version of the Diag Bios and it works with all the MVS Boards, however on some MVS boards the bios is soldered and not socketed so they need to be removed to use the Diag Bios.

If you have 3 MV-1FZS boards, maybe pick one to focus on and for the time being use the other 2 as parts. Simple things to try:

- pick the board in the best physical condition (no broken Traces, burned components, etc)
- if there is a backup battery, remove it as a precaution for now and check for any leakage damage
- when using a meter to check traces for continuity the “beep” function is helpful to identify if you have continuity, however to truly test the quality of a trace measure the resistance you want to see values close to 0 (example .19 ohms).
- as you mentioned GadgetUK has awesome videos and you can learn a great deal from them
- go to the NEO GEO Dev Wiki site for info on boards and Chip funtions
- go to the NEO MVS Scans site also great resource for images of boards and carts
- a logic probe is a useful tool to have as well

Hope some of this helps
 
Last edited:

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Thank you for the recommendations.. A logic probe is already ordered.
I checked out Neo Geo Dev for some pinouts and focused on one board now. I replaced some chips - one of them was the Palette RAM and the 74HC259 and also a Video RAM.. then I also randomly resoldered all pins and cleaned the board again.. I am making a little progress. I am seeing the cross hatch pattern when no cart is inserted (all though it flickers a little sideways sometimes).

When I insert a Cart it seems that the sprites are missing - the sound however seems ok.

Which Chip could be responsible for this kind of graphical behavior ?

Like I said I have one boards worth of chips around that I desoldered yesterday (however untested).

At least I could test all three bios chips and they all have the same behavior which means they are ok.

I already ordered most of the RAMs that are used in these boards - but shipping may take a couple of weeks so I have to see what I can do with my donor board parts for now.

Thanks
 

Attachments

  • 2231.JPG
    2231.JPG
    122.8 KB · Views: 123
  • 22344.JPG
    22344.JPG
    66.4 KB · Views: 124
  • 222312.JPG
    222312.JPG
    44.1 KB · Views: 120
  • 25543.JPG
    25543.JPG
    131.7 KB · Views: 119

Dropwire

Kuroko's Training Dummy
Joined
Jul 27, 2018
Posts
75
Thank you for the recommendations.. A logic probe is already ordered.
I checked out Neo Geo Dev for some pinouts and focused on one board now. I replaced some chips - one of them was the Palette RAM and the 74HC259 and also a Video RAM.. then I also randomly resoldered all pins and cleaned the board again.. I am making a little progress. I am seeing the cross hatch pattern when no cart is inserted (all though it flickers a little sideways sometimes).

When I insert a Cart it seems that the sprites are missing - the sound however seems ok.

Which Chip could be responsible for this kind of graphical behavior ?

Like I said I have one boards worth of chips around that I desoldered yesterday (however untested).

At least I could test all three bios chips and they all have the same behavior which means they are ok.

I already ordered most of the RAMs that are used in these boards - but shipping may take a couple of weeks so I have to see what I can do with my donor board parts for now.

Thanks

Are you certain the “Super Sidekicks” cart is issue free?

Are you still getting the RAM error you show in your image? And what RAM did you change RAM9 or RAM10 they are both for the Palette.

The issue you mentioned with the Crosshatch could be the Sync Line Level, the monitor your using, or a board issue. In your picture it looks like you wired direct to the JAMMA connector and then to the monitor, I don’t see a SuperGun or anything in between. You could see if the monitor has a Horizontal Hold control and try adjusting it to see if it helps with the crosshatch flicker. I had to use a capacitor and resistor voltage divider circuit to stabilize the sync on the video converter I built which includes an RGB amp. It makes the colors clean and stable and gives me s-video and composite out as well as well.
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Are you certain the “Super Sidekicks” cart is issue free?

Are you still getting the RAM error you show in your image? And what RAM did you change RAM9 or RAM10 they are both for the Palette.

The issue you mentioned with the Crosshatch could be the Sync Line Level, the monitor your using, or a board issue. In your picture it looks like you wired direct to the JAMMA connector and then to the monitor, I don’t see a SuperGun or anything in between. You could see if the monitor has a Horizontal Hold control and try adjusting it to see if it helps with the crosshatch flicker. I had to use a capacitor and resistor voltage divider circuit to stabilize the sync on the video converter I built which includes an RGB amp. It makes the colors clean and stable and gives me s-video and composite out as well as well.

Yes the cart should work - I have the same issues with another game as well.
Would you mind sharing the circuit to stabilize the sync ?

So my bet is still on the fast video RAM.. hopefully my issues will fade once replacing those. Also I seem to get some restart loops after a couple of minutes.

On my other board I found a broken trace under the LCSP2 so I tried to bridge it - but resoldering those back on is a pain in the *** ... The LCSP pins are bent and some of the traces are almost not there anymore.. so will be proper fun to get this thing back on again on my 2nd board.
 
Last edited:

Dropwire

Kuroko's Training Dummy
Joined
Jul 27, 2018
Posts
75
Yes the cart should work - I have the same issues with another game as well.
Would you mind sharing the circuit to stabilize the sync ?

So my bet is still on the fast video RAM.. hopefully my issues will fade once replacing those. Also I seem to get some restart loops after a couple of minutes.

On my other board I found a broken trace under the LCSP2 so I tried to bridge it - but resoldering those back on is a pain in the *** ... The LCSP pins are bent and some of the traces are almost not there anymore.. so will be proper fun to get this thing back on again on my 2nd board.

When I get home later today, I’ll send you the circuit diagram for the sync line, and I’ll also send you the diagram for the RGB (Color Amp / control) and Video encoder (composite and s-video).

I can try to Message them to you if your account is already unlocked, or email.
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
If you have facebook you can add me under the address "patrick.ryux" just put it at the end of facebook.com/ :) Thanks for your help
 

Dropwire

Kuroko's Training Dummy
Joined
Jul 27, 2018
Posts
75
If you have facebook you can add me under the address "patrick.ryux" just put it at the end of facebook.com/ :) Thanks for your help

The Facebook link didn't work for me, I sent you an email based on the address you have listed here in the forum.
 

ggallegos1

Cholecystectomy Required.,
10 Year Member
Joined
Oct 1, 2013
Posts
5,153
Have you tried clearing the RAM by turning the hard dips on at start up? Also, the bios is socketed, so removing and replacing that can maybe clear things up.
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Have you tried clearing the RAM by turning the hard dips on at start up? Also, the bios is socketed, so removing and replacing that can maybe clear things up.

Yes I tried clearing the RAM.. all Dips down and it wil display WORK RAM TEST and don't do anything.
I swapped the bios around with the same results and I don't have a Diagnostics bios yet - waiting for the chip to arrive still.
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Status of 2nd Board:

Since my 1st Board is waiting for Fast VRAM replacements I tried to do some things on my second board. I replaced the CPU and the LSPC-A2 (what a pain) and I am still getting a garbage screen with around 4 hz Clicking of the Watchdog.

I also replaced all the RAM Chips with Chips from another donor board (untested).

I can't feel any chips getting hot and I checked the board for broken traces with a loupe on both sides.

Is there any hope that once I got my diagnostic Bios it will display anything even now with the stock bios I only get clicking and garbage ?

EDIT: I also measured the oscillators.. the 24mhz one showed spot on as 24 mhz.. however the smaller one that should have 32.768 khz did not show anything plausible on my scope. Any other hints ?

Thanks again guys
 

Attachments

  • asdsadsa.JPG
    asdsadsa.JPG
    167.6 KB · Views: 88
  • mhz.JPG
    mhz.JPG
    102.8 KB · Views: 87
Last edited:

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
So today I socketed the Fast Video RAM (waiting for replacement) I also got a couple of New RAM Chips and replaced the Video RAM.

I still have broken graphics and strange colors. Any more hints what could cause this ?

I get no Error Codes with the stock bios.. Still waiting for my EPROM to flash the Diagnostic Bios.

Have a good day y'all
 

Attachments

  • soct.JPG
    soct.JPG
    96.8 KB · Views: 81
  • soct2.jpg
    soct2.jpg
    59.6 KB · Views: 78
  • soct3.JPG
    soct3.JPG
    99.8 KB · Views: 79

BIG BEAR

SHOCKbox Developer,
20 Year Member
Joined
Dec 14, 2001
Posts
8,230
OK. I had same the problem with a different model(The Garbled NEO GEO logo) and I ended up having to replace the 74LS245 (U3 is yours)next door to the 000-L0. The Diagnostic Bios will not pick up a faulty component. There's also one above SFIX.
BB
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
OK. I had same the problem with a different model(The Garbled NEO GEO logo) and I ended up having to replace the 74LS245 (U3 is yours)next door to the 000-L0. The Diagnostic Bios will not pick up a faulty component. There's also one above SFIX.
BB

Thanks I will replace those with some donor parts and see if this changes anything.
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
So I replaced the 2x 74LS245 now with the same result. Are there other ICs related to the Video Glitches or should I just replace all once I get my replacement parts from Mouser ?
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
My Mouser parcel arrived so I got a EPROM and flashed the Diagnostics Bios.

I get the following result (see picture)

Palette Address (A8-A12)

Any hints ? I will replace the palette rams for a start.


EDIT: I Checked the palette roms connection to the Neo-B1. All the traces seem to be ok (continuity).
Will replace the RAM now with some newer version that hopefully works as well
 

Attachments

  • pal1.JPG
    pal1.JPG
    95.2 KB · Views: 66
Last edited:

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Ok I replaced the Palette RAM with the newer version (different Package it uses SOJ-28) so I had to bend the pins outward and solder it then.

I still got the same palette error so I replaced the 74HC259 and then got all Tests Passed finally!

However...

I still have exactly the same graphic problems like before.. Losing my faith a little bit - So it will be some wild replacing in the dark I guess :(
 

Attachments

  • passed1.JPG
    passed1.JPG
    96.3 KB · Views: 64
  • RAM2.jpg
    RAM2.jpg
    100.1 KB · Views: 64

BIG BEAR

SHOCKbox Developer,
20 Year Member
Joined
Dec 14, 2001
Posts
8,230
Check the SFIX and the two chips underneath,the 74LS273's
BB
So I replaced the 2x 74LS245 now with the same result. Are there other ICs related to the Video Glitches or should I just replace all once I get my replacement parts from Mouser ?
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Check the SFIX and the two chips underneath,the 74LS273's
BB

Hey.. Replaced the 74LS273.. Same result.. not sure how I should check the SFIX ? And I am also not sure if it can be related to the SFIX as it says its more used for menus etc.

Any other suggestions greatly appreciated
 

BIG BEAR

SHOCKbox Developer,
20 Year Member
Joined
Dec 14, 2001
Posts
8,230
Hey.. Replaced the 74LS273.. Same result.. not sure how I should check the SFIX ? And I am also not sure if it can be related to the SFIX as it says its more used for menus etc.

Any other suggestions greatly appreciated

74LS32(u1) and the other (u13) & Ls08(u15)
BB
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
74LS32(u1) and the other (u13) & Ls08(u15)
BB

Thanks - replaced those 3 IC's with new parts - didn't change anything :(

See pics
 

Attachments

  • p1.JPG
    p1.JPG
    151.2 KB · Views: 50
  • p2.JPG
    p2.JPG
    64 KB · Views: 52
  • p3.JPG
    p3.JPG
    189.5 KB · Views: 51
Top