my new MV-4F problem with video

dragonpt

dragonpt

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so today after 1 week, my Mv-4F, arrived. But im not getting video (didnt test the sound at this point)

the supergun i use, works great with my MV1FZ and MV1B, with this one, i get some strange picture :






what do you guys think, it can be?

please help:(
 
Xian Xi

Xian Xi

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If the board is dirty I'd wash it. Make sure you remove any batteries or socketed chips. Either way you need to check the board for broken traces and corrosion.
 
dragonpt

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Xian Xi said:
If the board is dirty I'd wash it. Make sure you remove any batteries or socketed chips. Either way you need to check the board for broken traces and corrosion.
Click to expand...

yes its all dirty
i thought it was a psu problem, becouse its an 4 slot, needs more power, i use a normal pc atx power suply, and i put some 7A fuse on 5v line (was recomended for the 1 slots)

i will try to clean it up a bit more

thanks (:
 
dragonpt

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so i clean it all up, both pcbs, and in the lower pcb, i saw that someone did some repair on it (check red circle on both pics)

tested again, and all the same bad picture

what a hell, is this repair?







Uploaded with ImageShack.us
 
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C

CafeineCake

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Can you read what is on that ship? One you have that you can get the datasheet and see what pin is shorted to the GND (Most likely).

I am pretty sure ppl more familiar with this mobo will tell you why someone would do something like this.
 
Xian Xi

Xian Xi

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The problem isn't that chip, that's normal.

You need to check traces from the various rams.
 
dragonpt

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Xian Xi said:
The problem isn't that chip, that's normal.

You need to check traces from the various rams.
Click to expand...

i found out 2 problems ..........


problem 1 solved :

thanks for the help, i ask my wife to push hard 1 by 1 the memory rams chips (with some tiny pillers i have), and bummmm VIDEO ON, clear picture :multi_co::mr_t: so i take out the old solder, put some new solder on, and now its ok.

problem 2 :

its also a psu problem, sometimes (after problem 1 is solved) the mvs boots only sometimes, like i said before i have an 7A fuse on the +5v line (its is recomended for the 1fz), after i take out the fuse, and put some wire on the fuse holder, the mvs now boots everytime, BUT i do not want to have the mvs having a direct +5v power from an atx psu, what fuse (A) do you recomended? i look hardmvs, and in this mvs pcb, there no info on the amp values for 12v and 5 v lines


thanks again for the replys, only need 1 more info on this:drool:

EDIT :

just found a new problem: sound is a bit bad (trash), i think im going to recap the sound capacitors...
 
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dragonpt

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edit 2 : well if im going to need to recap the sound caps, maybe i should change that batterie, before it leaks all over pcb...
will search for a direct replacement
 
Tyranix95

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Good idea.

My 2-Slot came with a GS SAFT 3.6V 50mAh Ni-Cd battery--PN# GB50H-3.

I replaced the OEM battery with this NiMH - Nickel Metal Hydride Battery 3.6V 80mAh. Works fine.

But, XX has a battery mod kit for the NEO. Basically, it allows you to start using easy to find COIN CELL batteries with a NEO board. I've been thinking about it. You may want to check it out.
 
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Xian Xi

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Sounds like the PSU is failing. The 4 slot only pulls a max of ~6A on the +5v line when fully loaded. You can putter a higher value fuse like 8A but I think you need to test your PSU and change it.
 
Tyranix95

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In the past, I used either an ATX or an AT PSU to run my MV-2F board. The power specs on the side of these PSUs were almost identical to the HAPP PSU that I use now. Their amps were a little higher. But these computer PSUs ran my NEO just fine.

Now, I use an Ultimate Power Supply with On/Off Switch - 150 Watt with my MV-2F. And my NEO runs great. And I dig the voltage adjust knob. :D

HAPP also has a Power Pro Ultimate 150 Watt Power Supply with External On/Off Cable for the NEO; however, I personally like the internal on/off switch on the ULTIMATE PS.
 
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channelmaniac

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ATX power supplies with 3.3v outputs are poor choices to use on arcade systems that do not use 3.3v. Without loading them properly the power supply can do screwy things.
 
N

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Changing the fuse to a higher rated fuse wont make any difference unless youre blowing it, a 6 amp fuse wont blow at 6 amps either. That is the nominal current rating. You can probably pull 8 amps through it for a short amount of time and not blow it.

If you check the current flow, youll probably find its not pulling 6 amps anyway, i run 2 different 4 slots off a 5v power supply with only a 3amp capacity, and never had an issue. This may be different if youre using the onboard audio amp, but that shouldnt matter cause youve got the 12 volt supply for that.

I also use an old 250 watt ATX supply to power a Hyper 64 NEO-GEO and its always been fine too, so id have to think there is an issue with the supply youre using, or an issue with the board still if its not happening on the other 2 boards youve got.
 
N

NEO-GEO man

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Id be interested to see the wave form coming out of this power supply though and see how smooth it is, if its old, it may have a fair bit of ripple to it, and under more load, that will cause undervoltages.
 
dragonpt

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well it just blow up the 7a fuse,i replace the psu with the one i had on my pc,after 1 hour of testing,again with the psu,anouher fuse blow.after check the voltages on both psu i get 5.20 to 5.10v on the 5v line on the molex conector,but only 4.05 to 4.15v on the jamma conector.wtf? I think the board is having some voltages spikes.same issue on both psus
 
N

NEO-GEO man

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There is a short in there somewhere.

If my 4 slotters can easily run fine on a power supply that can only deliver 3 amps, yours should shit it in no problems with an ATX clearly capable of much more.

Check the wiring to see where it is shorting, and make sure youve got it all wired up properly.

Where is this fuse youre blowing? What part of the power supply? The low voltage side or the supply side?
 
Tyranix95

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Jamma SuperGun (... I soldered the fuse holders onto the the board and the power lines from the PSU. The 5v uses a 10A fuse, and the 12v uses a 1A. ... Each wire was also covered with heat shrink tubing to prevent accidental power grounding. ....)

sgjamma.jpg


-----

Bob Robert's basic AC wiring diagram (We have 110VAC into the cab and now we need to fuse the hot side....The hot side of the AC cord can now be fed though a fuse holder with a 3 amp fuse in it, and on to the other side of the AC filter.)

basic-ac.gif
 
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dragonpt

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thanks for the replys
yes i had fuse holders, exaclty like those, but i just took them out, after blowing 3 fuses.

after long hours, looking to the pcbs, i found a short on the 5v line, that was connected to a GND, by a small solder line,took out the extra solder, and no more blowing fuses xD

Now, im waiting for my caps, and maybe tomorow, i make the battery mod, have here an extra cell battery from my nokia 6630 (lol) :cool:
and it just haves the right voltage 3,6 v hehehe
 
dragonpt

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NEO-GEO man said:
Glad you got it fixed ;)
Click to expand...

glad i have you mates,to help us out. Very nice community here,i was 2 years away from the foruns,but thats past.tanks maybe my little experience with mvs's neo cd's can help others
will update topic,when all is done,im also building another supergun,i just thought its easyer to build a new one instead of upgrade the old one.
now i just need uhe time,im working 16 hours a day,and only 1 day of
f. Glad to have my cell phone to post here...
 
dragonpt

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little update:

so i just found why the mv4f only booted sometimes, i'v try 3 psu's, always the same problem, and those same psu's always booted my 2 mvs 1 slot...

after measure the A, on both +5v, and +12v lines, i saw, that these board needs alot more amps on both those lines, the solution: i just tie together all the molexs from the psu, and now it always boot at the first try.








Just find out that the jamma/mvs to scart pinout is whrong about the sound pins, the pinout, tells you to connect to pins 2 and 6, but the correct pins is 1 and 3

pin 1 Audio Out Right
pin 3 Audio Out Left + Mono

its a bit messed up, im still testing, and the supergun is not yet completed
 
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N

NEO-GEO man

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Sorry, i didnt know that is how youd wired it up or id have said something sooner. If you want it abit more tidy, open up that power supply and de-solder all the wires you wont ever use. Then join all the 5volt wires together inside the PSU, and run one larger cable out, and do the same for the 12volt, and for anything else youll likely need, including the common. This way, youll only have 3 or 4 wires comming out of the PSU, and itll be alot more tidy.

Also with the RGB lines there going to that SCART socket, do you have resistors in line with them? 220 ohm would be about right if you dont.
 
dragonpt

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NEO-GEO man said:
Sorry, i didnt know that is how youd wired it up or id have said something sooner. If you want it abit more tidy, open up that power supply and de-solder all the wires you wont ever use. Then join all the 5volt wires together inside the PSU, and run one larger cable out, and do the same for the 12volt, and for anything else youll likely need, including the common. This way, youll only have 3 or 4 wires comming out of the PSU, and itll be alot more tidy.

Also with the RGB lines there going to that SCART socket, do you have resistors in line with them? 220 ohm would be about right if you dont.
Click to expand...


well, i didnt put any resistors on the RGB lines, cause the colours are great this way, i usually put sume 75 Ohm resistors on RGB lines, on my other consoles cables, but this one is just fine this way.

well, if i find some large cables, i will solder them into the psu, for the time being, its ok this way.

<3
 
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