installed Ms Pac power supply kit- help needed

[vintagegamer]

Hi All,

My Ms Pac machine's been down for about 2 months now, and I took the group's advice here and bought one of the ArcadeShop power supply kits.

I just hooked it up and in the upper left corner, there is an LED bulb that lights in green yellow or red, depending on the level of +5 voltage.  It is currently at yellow.

My question is, does the supply need to be adjusted for the game?  There is a little dial under the LED that looks like it can be adjusted, but I'd like a 2nd opinion before turning it.  I got the seller's v/m so I had to leave a message.

Has anyone else had this issue?  Everything else works on the game: marquee light, sound, and the monitor showed no issues before this happened.

Thanks in advance,

vintagegamer

[RayB]

Yes. Usually the led will be green. Red means too much juice.

Get a multimeter and check the voltage when adjusting. You measure the +5v.
You need to start with it just below 5.0. Turn the machine on, check what shows up on the monitor.

Then turn off power. Adjust that knob very very little, and turn the machine power on and off to reset the game board. Check the voltage again to know where you're at, and check what shows up on the screen.

Eventually you find the sweet spot that the board needs to work (could be anywhere from 4.8 to 5.4... or more). This is assuming your board works.

[vintagegamer]

Thanks for your response, Ray-  Actually, while I was awaiting responses to my post, I decided to go out and give the dial adjustment a try.  This is what I did:

1. turned off the machine
2. moved the dial counter clockwise just slightly
3. powered up the machine and checked
4. went back to #1

After doing this repeatedly to where the dial would no longer go any further counter-clockwise, the light still stayed yellow and the monitor never powered up.  I then did the following:

1. turned off the machine
2. moved the dial clockwise just slightly
3. powered up the machine and checked
4. went back to #1

I went all the way to where it would go clockwise no further, and there was still no change (in the light color OR the monitor power).  I'm assuming the powering off and on would have given the game board time to reset, wouldn't it?

This is really starting to suck.  I just want my Ms Pac back.  Please post if you can provide any insight.

vintagegamer

[RayB]

The monitor doesn't power on?!?

The power supply you installed has NOTHING to do with powering the monitor.

I suggest you start from the beginning and post what your original symptoms were and how you came to the conclusion to buy that power supply kit. (Or is there another thread on this forum where you discussed this already?)

[vintagegamer]

Thanks for your help Ray.  It all began here:

http://forum.arcadecontrols.com/index.php?topic=56580.0

[grantspain]

i think you have been barking up the wrong tree,99.999 percent if you get game sounds and no picture then its a monitor fault,i know you swapped it but how certain are you that the other monitor was working in the first place(and did you meter the voltage at the monitor input plug?)

[vintagegamer]

Thanks for your help grantspain-

I actually did not do any meter checks with the other monitor.  The monitor is a used one, so as much as I hate to admit it there's always the chance it could be shot too.

If you can tell me how to check what you're referring to without blowing myself up, I'll be glad to do a check tonight and post my results.

Thanks,

vintagegamer

[grantspain]

get yourself a multimeter,set it on a/c,make sure the probes are in the correct sockets on the multimeter,set the range of the meter to more than 100v less than 1000v,put the red probe into one the monitor input plug pins and the other probe into the other pin-if you read 110v or thereabouts then your voltage is correct-if you don't read 110v then trace the monitor supply wire to a fuse/switch or connector-lets take it from there

[fredster]

If the monitor is working, then it should make that "humming" noise when it's running if there is a picture there or not.  The tube neck should glow in a minute or so.

You should also hear the degaussing coil kick in the first time you power up.  If there's power.

But does the game coin up and play blind?  IF it doesn't then you have that power supply hooked up wrong or one of your wires are not secured correctly.

[vintagegamer]

If the monitor is working, then it should make that "humming" noise when it's running if there is a picture there or not.  The tube neck should glow in a minute or so.

You should also hear the degaussing coil kick in the first time you power up.  If there's power.

But does the game coin up and play blind?  IF it doesn't then you have that power supply hooked up wrong or one of your wires are not secured correctly.

I am hearing a humming when behind the machine after powering up, but I think it's the fluorescent bulb up top.  I let the machine stay on for a bit last night and checked the back, but didn't see any "glow" on the tube, so I'm guessing power isn't getting there but not sure.  The game does coin up and play blind.  Thanks for your input and keep the questions coming.

vintagegamer

[vintagegamer]

get yourself a multimeter,set it on a/c,make sure the probes are in the correct sockets on the multimeter,set the range of the meter to more than 100v less than 1000v,put the red probe into one the monitor input plug pins and the other probe into the other pin-if you read 110v or thereabouts then your voltage is correct-if you don't read 110v then trace the monitor supply wire to a fuse/switch or connector-lets take it from there

Thanks for the info- I have a multimeter, but when you talk about the plug pins, do you mean the 2 wire connector that comes off the chassis board and has the black/white wires going into it?

vintagegamer

[fredster]

If the game is playing blind, then check the connections (RGBG sync) to the monitor.

You can jab up to 5v on the R G B with the ground to test it. You can do that from a power supply.
Bob Roberts has a home made tester on his site.

That will cause the monitor to flash. If the board is booted, it's playing, it should be okay.

I think you have a monitor problem. I think you fixed your power supply.

Look up Bob Robert's site and do some investigation. You probably have an Electrohome G07 CB0 in that machine.

[grantspain]

get yourself a multimeter,set it on a/c,make sure the probes are in the correct sockets on the multimeter,set the range of the meter to more than 100v less than 1000v,put the red probe into one the monitor input plug pins and the other probe into the other pin-if you read 110v or thereabouts then your voltage is correct-if you don't read 110v then trace the monitor supply wire to a fuse/switch or connector-lets take it from there

Thanks for the info- I have a multimeter, but when you talk about the plug pins, do you mean the 2 wire connector that comes off the chassis board and has the black/white wires going into it?

vintagegamer

yes

[vintagegamer]

OK-  progress made..  checked the black/white wires coming off of the orig power supply/adapter, and juice is making its way from there to the chassis board.  Multimeter read about 118V, which I believe is good.  Also the chassis has part # GO7 CB0 on it.  Again, the tube never warmed up or "glowed", so I'm guessing we're getting close to it being the chassis board. 

Is there a next step where I can check voltage?  Thanks again for the help with this.

vintagegamer

[RayB]

You're in the same boat I am with the G07 in my Centipede.  I'm waiting on getting a cap kit. Gonna also check for and reflow cold solder joints.

[grantspain]

next step is to set your meter to d/c volts and read the outputs on the psu(+5 and +12),also is there an a/c output to another board from the psu
one other thing when you fit the new psu you must have to disconnect the old psu connections to the game board,is this correct?
another thing i always do when i go to a machine with no screen is to turn up the screen volts on the flyback a little to see if i get a white-ish screen

[fredster]

Yeah there's another place to check.

See if you are getting signals to the monitor.  Set that multimeter to DCv.
Take off the monitor's connector to both the power and the R G B connection.

Take the black probe and put it in the Black wire (Ground) and the red wire and put it in the R, then the G, and then the Blue.  You should see a variable voltage up to 5v. If you see that, then you are getting a signal from that board. If not, then the game isn't giving you a video signal.

If you don't have a video signal, you have a chip out on the board. (But I'd bet you don't if the game is playing blind)

Then set the multimeter to ACv and check the AC and make sure it's getting 115v from the transformer.
If it isn't, you have a fuse out.  If it is, then you have a High Voltage problem or the Blanking circuit's cap is bad.  Look for Bad Caps in that monitor.

Do you know how to identify a bad cap visually?

[Lutus]

I just fixed a G07 not a month ago in my digdug machine.

I ordered the capkit/HOT/flyback from Bob Roberts.

After I replaced these things it still didn't work... odd, so after 7 hours of idiocy and two small shocks later, replaced the fuses and BAM works like a charm!!!  

The G07 is easy to work with.  

My suggestion is to get the above package from Bob Roberts.  It is less than 30 dollars and I am 68% sure that will get it going again!!


EDIT::  My diddug machine also played blind like yours does and it also was getting around 116V to the monitor.  Exact same symptoms.  When I did the cap kit one of the caps only had one leg, thus creating an open circuit which blew the fuse.

EDIT2::  Note, I also replaced the flyback and the HOT while I was in there.  These are other common faulty components.

[vintagegamer]

Thanks guys-  Going on Lutus' info, might it be best for me to just buy a rebuilt monitor chassis?  I would rebuild the existing one, but I know to change the fuses there is soldering required, and I learned long ago that soldering is not at all one of my gifts (funny thing is I can use a MIG welder w/no problems!).

It does sound tho like the culprit is the blasted monitor chassis.

[vintagegamer]

Yeah there's another place to check.

See if you are getting signals to the monitor.  Set that multimeter to DCv.
Take off the monitor's connector to both the power and the R G B connection.

Take the black probe and put it in the Black wire (Ground) and the red wire and put it in the R, then the G, and then the Blue.  You should see a variable voltage up to 5v. If you see that, then you are getting a signal from that board. If not, then the game isn't giving you a video signal.

If you don't have a video signal, you have a chip out on the board. (But I'd bet you don't if the game is playing blind)

Then set the multimeter to ACv and check the AC and make sure it's getting 115v from the transformer.
If it isn't, you have a fuse out.  If it is, then you have a High Voltage problem or the Blanking circuit's cap is bad.  Look for Bad Caps in that monitor.

Do you know how to identify a bad cap visually?

Thanks Fredster-  This is all new to me (troubleshooting video games, not the overall electronics bit).  I have never seen a bad cap, so if you can tell me what to look for that would be great.  I also thank all of you for your patience with me on this.

[vintagegamer]

next step is to set your meter to d/c volts and read the outputs on the psu(+5 and +12),also is there an a/c output to another board from the psu
one other thing when you fit the new psu you must have to disconnect the old psu connections to the game board,is this correct?
another thing i always do when i go to a machine with no screen is to turn up the screen volts on the flyback a little to see if i get a white-ish screen

Actually, the new power supply conversion kit did not require disconnection of the existing one (or at least not that I could tell- did not come with instructions). 

It has an interface cable where one side of the connector hooks to the game board, and then the other has a male end for the original connector to hook onto.  It somehow feeds from the existing cable and the new one together.  Hope I'm explaining this clearly!

[fredster]

I'm talking about the electrolytic caps. The ones that look like little batteries.  (they are a kind of little battery actually) They have a coating on them and on top of the "can" there's a split line(s). You can see these lines.

When the caps are new and minty fresh, the coating is uniform on the top of the cap. The split lines are there, but they have no contour.

Bad caps can be spotted because the coating is streched.  The top of the can is bulged out.  It may be creased at the split lines. The whole cap may be rusty.  Any one of these things makes the cap suspect. And for as much as they cost, they are usually all replaced whenever the monitor is serviced. 

To actually test it you need a special tester (the ones on the multimeters are very falliable).  You have to remove it to do it anyway. So most of the time they are pitched.

A cap kit costs about $8-$10 shipped. Well worth the effort on that monitor. New caps keep the IC's and transistors from failing.  They also restore the colors and the full adjustment range of the monitor.

My guess is you have something scrwed up in the ground or sync to that monitor or you have blown a fuse. If it was running when the p/s went out, then it's probably still working.

As a stupid question, you did check to make sure you didn't change the contrast setting or make the monitor black did you?  You can adjust it with the "screen" knob on the Flyback transformer. Turn it all the way both ways after about 30 seconds of the monitor warming up. You should be able to turn the monitor white. "screen" is the brightness knob.

[grantspain]

sorry but to have the psu still connected don't sound right to me(could be wrong though) i can see how it works by the photo-it interfaces with the original edge connector,you should email the guys you bought it from to check
you still have not proved whether the fault is on the monitor/psu or game board yet-have you tried turning up the screen volts(its the first thing i do and i have been fixing arcade machines for 20 years,you tend to get quick fault finding knowledge during that amount of time)

[vintagegamer]

sorry but to have the psu still connected don't sound right to me(could be wrong though) i can see how it works by the photo-it interfaces with the original edge connector,you should email the guys you bought it from to check
you still have not proved whether the fault is on the monitor/psu or game board yet-have you tried turning up the screen volts(its the first thing i do and i have been fixing arcade machines for 20 years,you tend to get quick fault finding knowledge during that amount of time)

I have not yet turned up the screen volts.  Tell me where I would adjust this and I can try tonight.

Thanks!

[grantspain]

its one of two adjustments on the flyback transformer,the other being focus

[vintagegamer]

You know what's really funny?  I could SWEAR that although the screen wasn't at normal brightness, that I thought I was still seeing something moving around on the game map.  Is it possible this could have just dropped low or something?

Either that or I need medication.   

[grantspain]

dirty contacts in pots,capacitor faults,dry solder joints,low +5volts on the game board all can cause a picture to go dull,thats why i do the flyback shuffle

[RayB]

I thought he said he had no neck glow?

[grantspain]

we train our eyes to spot a neck glow,sometimes the glow is dim and light pollution can block out the glow-but its always easy to look for something when you know what it looks like-does that make sense

[Lutus]

I agree that before you buy a replacement chassis or a new monitor take the couple days to...

A) get better at soldering
B) instlall a capkit and a new flyback and a new HOT

Go ahead and order the kit from Bob Roberts and while you are waiting for it to come in, find an old piece of junk printed circuit board (anything you can find) and learn how to desolder/resolder/continuity check.

It is a much more economical and rewarding experience.

Here is a tutorial on how to do all of these things...
http://homearcade.org/BBBB/g07repair.html

How to use ohmmeter:
http://homearcade.org/BBBB/om.html

Look halfway down this page:  5 different documents about the G07 (very helpful):
http://www.lizardlickamusements.com/pages/documents

[vintagegamer]

Thanks to all of you.

I'll take another crack at the machine tonight and post updates.  You all have been a HUGE help.

[Lutus]

Here is what you need to order from Bob Roberts:

"Electrohome GO7 Flyback Repair Kit  $26.00"

It can be found on this page:

http://therealbobroberts.net/parts.html#flyback

In order to buy from Bob you must send him an email of what you want (copy and paste the second line of this post, the line in quotes).  In the email tell him where you live and your name and what not, he will respond with a followup email telling what to write him a check for and you must mail the check to him.

He is a very reputable dealer (one of the best) so do not be concerned about sending a check.  Also, only email him when you are 100% ready to order. 

Hope that helped.

[ChadTower]

Bob is the man.  Order with confidence.  I have ordered so many times he probably has my address as a text editor macro.

[vintagegamer]

OK so here's the update-  I tried adjusting the brightness switch on the chassis board which is next to the focus button, and nothing happened.  I'm thinking at this point it's pretty safe to assume the power disconnect is the chassis board.  Nothing is apparently getting to the monitor.

I appreciate the offers, but I've tried repeatedly and failed with other soldering attempts in the past.  So is there a supplier anyone recommends for a rebuilt chassis board?  Or, if you're good at it, I'll be glad to send you the one out of the machine to rebuild and throw you a few bucks for the effort.  Sorry folks but I know my limits!

[RayB]

You could buy a working used monitor for the same price as it would cost to ship your broken one out to someone.

[grantspain]

did you check the fuses on the chassis(i think there is two),thats not too technical

[Lutus]

Agreed, at least check the fuses.  But be sure about those things, they can look good, but still be bad.  You must use a meter on them.

[ChadTower]

Call around for local indy tv repair shops.  They can fix arcade monitors.

[fredster]

If you want to keep that machine for ever and ever, buy a new monitor from Betson Imperial.  They have them shipped for less than $200.  They are Kortek monitors but they look good and it will mount right into that cab.

That cab has those mounting brackets and it's easy.

But don't give up on the G07.  They are easy fixed.  Download the manuals for it and take it to a TV guy or radio repairman. Give him the caps and the kit from Bob and he can fix it for you.  Cost you about $50 + 30 for the parts to get it fixed.

[Stingray]

You could buy a working used monitor for the same price as it would cost to ship your broken one out to someone.

Not if he just pulled the chassis and shipped it by itsself.

-S

[fredster]

TV repair shops can fix 'em. Just bring it in. 

[RayB]

Not if he just pulled the chassis and shipped it by itsself.

Of course. Silly me!

Fred: I once popped into a TV repair shop to get an estimate on doing a cap kit for me. First, I had to explain what a cap kit was. I said it's "replacing all the capacitors". His response was "that's alot of capacitors".

[ChadTower]

Then you picked a crappy TV repair shop.  They're not all like that. 

[fredster]

The guy I took mine too told me I was wasting my money and showed me how to work on 'em. Depends on who you know I guess.

The worst they can say is "nope".

But it isn't that big of a job anyway. Bob Roberts and the rgvac have write ups that make it easy. The first one is really nerve racking, but after that you get a pretty good feel for it.  You do need to go get a soldering Iron from radio shack, and a solder sucker, and some solder.

It's good practice. 

[ChadTower]

My first was nerve racking.  That is true.

Now I could cap a monitor without any issue whatsoever.