Street Fighter 2 Machine, what else can I check?

heyricochet

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I should start by saying this is my first arcade machine, so don't presume that I checked anything thats standard, I'm working off of google searches and other electronics experience. So I picked up an SF2 machine for 100 bucks, had a broken monitor but it would power up and you could play blind. Got the machine home, and now nothing works. Checked the sound wires to see if those got knocked loose, but they trace 8ohm all the way back to the jamma harness.

Then checked the power supply, and I have about an 8.5 V gap between -5 and +5 as in, if the +5 is +5, the -5 is -3.5. I'm guessing there isn't any mystery knob to widen this gap and I just have to replace the power supply? Or, can I just replace some of the components inside to easily make it output the proper voltages? I'd rather spend 2 bucks at digikey then 25 on a new supply. If I do have to get a new supply is there any other way to check to see what else could be broken so that I order all the parts I need at once?

Also stupid question, but as long as I can supply all the voltages to the board it should output sound correct? It doesn't have to have anything else hooked up.
 
Sometimes you will not hear any sounds until you coin it up. Have you tried that?


Some power supplies can be rebuilt, we need to know what power supply you have in order to send you in the right direction.
 
I should start by saying this is my first arcade machine, so don't presume that I checked anything thats standard, I'm working off of google searches and other electronics experience. So I picked up an SF2 machine for 100 bucks, had a broken monitor but it would power up and you could play blind. Got the machine home, and now nothing works. Checked the sound wires to see if those got knocked loose, but they trace 8ohm all the way back to the jamma harness.

Then checked the power supply, and I have about an 8.5 V gap between -5 and +5 as in, if the +5 is +5, the -5 is -3.5. I'm guessing there isn't any mystery knob to widen this gap and I just have to replace the power supply? Or, can I just replace some of the components inside to easily make it output the proper voltages? I'd rather spend 2 bucks at digikey then 25 on a new supply. If I do have to get a new supply is there any other way to check to see what else could be broken so that I order all the parts I need at once?

Also stupid question, but as long as I can supply all the voltages to the board it should output sound correct? It doesn't have to have anything else hooked up.

congratulations on your purchase, first off, but if your +5 is set to 5-ish volts like you say, and the -5 is outputting at -3.5, I'm going to have to say your power supply isn't working right.

I think you know that the +5 is regulated, and a switching power supply generates all the other voltages on its own. I'm going to have to say if your -5 is off, your +12 is probably going to be under 12 volts too. this will cause your game to have no sound, if so.

as you're also well aware, I think you know that there's a dedicated member base here that will fix just about anything that they can. one such monster is not switching power supplies. I'm not doubting your abilities here, but the time and effort you'll spend trying to diagnose a broken power supply will be a total waste versus buying a whole new unit. when you buy new, you can eliminate a lot of factors in the troubleshooting process (though there's been a few instances where new power supplies were defective too).

only time you ever mucker around with power supplies is if they're the linear kind. :)

post your kind of PSU though. there was a series of Peter Chou screw terminal units that shipped with a few different games around that time period that have problems, and I think KenLayton said that it's just a resistor replacement and you're back in business.

I still say go ahead and replace it though. what's the worst that happens, it doesn't fix the sound problem? you could always use it on another game you buy later too, and spare parts are never a bad thing in this hobby. (especially if you're running a business with the equipment like me)
 
The PSU is a Powermaster XII. Google doesn't pop up any info but powermaster is a pretty generic name. I'm getting a new one from Bob Roberts, as it seems thats the place to go. Anything else that typically breaks that I should pick up while I'm ordering something? I'm going to get a cap kit at least.
 
Most SF2 boards are pretty picky about 5v. There may be other problems, but swapping out that PSU is definitely the first thing to do.
 
Thats exactly what I hoped to hear, hopefully this'll be a pretty easy one to get up and running for my first project.
 
Trying to figure out what the monitor is, only identifying feature (besides the serial #, no product #) is a logo that says PS and says "Another quality product" surrounding the PS logo. Any ideas?
 
take a pic of it, the crack team of monitor specialists can probably tell you right away. lol
 
DSC_7591.JPG


DSC_7590.JPG


DSC_7589.JPG


Hows that?
 
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hard to tell, I'm not familiar with that one. looks much like this though:

mon14.jpg


maybe someone can prove me wrong. :)

EDIT: your best bet is to start a thread in the Monitor Repair forum... maybe that's one no one's catching it here.
 
Man you're good. It has to be that one, it has the same switches at the top left, same shielded flyback area, same type of v-sync and such adjustment knobs. Perfect.
 
Man you're good. It has to be that one, it has the same switches at the top left, same shielded flyback area, same type of v-sync and such adjustment knobs. Perfect.

I was getting worried, I was starting to run out of oddball monitors on Bob Roberts monitor ID page, and that was the last one. lol

I don't know any model differences or anything. I tried going to Kortek's site, but they have NOTHING about arcade monitors on it, so I don't know anything about the model differences or whatever for these.

you said it was playing blind, did you make sure that the monitor's getting juice? I got a Blitz '99 at auction where the monitor wouldn't come on and it turned out to just be unplugged (and highly fucked out of adjustment LOL). sometimes it'll be plugged in but there's no power, so if it's a cab that looks like it's been 'molested' there could be something else that came disconnected elsewhere. best way to verify is that you're getting voltage at the monitor's power connector testing with a DMM.

maybe you'll get lucky and it's something simple like that. I love stupid, simple solutions.
 
if you look at the back side of the monitor chassis, you will most likely find some printing along the edge that says "K1-2-V0". Several Kortek chassis models had this board. I just fixed one labeled as a KT-2001SF. You will typically find the label on the right side of the cage around the flyback if it hasn't fallen off.

You can find a cap kit listing here:

http://forums.arcade-museum.com/showthread.php?t=120064

Check for a cold solder joint on L402, and do a cap kit and see what happens...
 
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