Sanyo 20 ezv help

[Kevin Mullins]

Ok... here's where I'd like to see if you have the 16vdc you should have.

There are actually two spots you can check, they are on the same trace.
Top side pic: http://www.we-r-art.com/Kev/Sanyo01.gif
Bottom side pic: http://www.we-r-art.com/Kev/Sanyo02.gif
When you look at them they will both look like holes that have nothing that belongs to them.
And they both have solder on the bottom side.
The first one is right below the text for C165.
The second oneis right above resistor R161.
There are acouple missing components on mine, don't mistake those holes, they are labeled C613 and R452.

There is another hole near them, that has NO solder on the bottom, through hole, ignore that one. (different trace) (right next to the C for C301)

But I want you to try and measure these two spots for the 16VDC .... FIRST.
Not sure if your meter probe will fit down in there, might have to stick a pin in the hole to test it. (just don't touch anything else) 

There's a largeish resistor on the inverter board where the power goes in, so I'm bettin' this drops the voltage a tad. So the 16VDC might make a difference in color and such for ya. I wish mine was together, I'd check all this out first hand, but you seem to have a good handle on it so far.

[Kevin Mullins]

Oh... and in case anyone else was trying to figure out what we're messing with at this point.

[rfr341]

Good news I made all the adjustments like you guys told me to and it looks awesome. The retrace lines aren't visible and the colors look excellent, nice and bright. I am going to check out those two spots to see if I have 16vdc and let you know Kevin. My plan is to replace the Blockout pcb with a Double Dragon pcb which should arrive this week, but I think I will use this cabinet as a universal cabinet for different games. I can not put into words how ecstatic I am to have this cabinet up and running, now I  just have to replace
the monitor in my APB cabinet with a medium resolution monitor which I maybe getting this week and all 8 of my cabinets are working. All is left to do is the cosmetic work on them (like painting and new trim). Thanks again to you all for your help, being new at this I have been learning as I have been going along you and the information I have learnt from this website and from those who have been helping me has been priceless. You guys rock!

[Kevin Mullins]

Glad to hear all is looking good on it.... and glad to be of some help.
I'm no seasoned vet at this stuff, but I have had my share of "misfit" projects and had to learn alot quickly.
It's all in the fun of the hobby though.

That blockout is kinda challenging, but you would have to add that third button to play it right. (3 on the CP and 1 on the joystick)
But you might want a third button anyways if you plan on making that cab "universal".
 
So are ya just planning on replacing that mis-matched medium resolution monitor for the APB?
What are the other cabs you have up and running now?

[rfr341]

Hey Kevin, I agree with you it is a fun hobby. The other games I have up and running now are twin cobra, tiger heli, t-mek, rastan, renegade, mat mania, and now my nintendo cabinet . As for APB that is my plan to replace the standrard resolution monitor that it came with for a medium resolution monitor so the game will work, I found a guy locally who has a 19" medium resolution monitor for sale. I also have pcb's of wrestlefest and mania challenge. Those are the games I have for now so I can't wait to get all the work done on them so I can enjoy them, they are games I remeber playing when I was a kid.

[Kevin Mullins]

Could I get you to do me one other favor..... for information purposes.
Whenever you get a chance to poke around that Sanyo 20-EZ again, no hurry.

Measure the deflection yoke ohms.   (with monitor power off)
Set Your Multimeter to Low Ohms ( 200 )                 
Measure between Red & Blue and then between Green and Yellow
Just unplug it and measure like pic below.

I'm just trying to complile some data while we're at this.
Thanks.....

[rfr341]

No problem Kevin, I will do that for you and let you know my findings

[rfr341]

Got my replacement monitor for my APB today and it works great, finally I can play it. The colors on the monitor look awesome. I got those numbers for you Kevin for the deflection yoke. The ohms reading between the yellow and the green was 54.6 ohms and the reading I got between the red and the blue was 2.2 ohms, if you need anything else let me know, I have not had a chance yet to measure for the 16vdc. The only real thing I have to do now is swap the monitor in one of my cabinets that looks like is on its way out which has a 4600 chassis with the monitor I took out of my APB and has a 4900 chassis, I figured it would be easier to change the tube and chassis rather than have to take the 4600 yoke from the old tube and put it on the tube with the 4900 yoke. Almost all done....

[FrizzleFried]

Question:  Has anyone determined if these holes are,  in fact,  the 16VDC location so poor saps like me with a Nintendo monitor that DOESN'T HAVE the leads come off them can add a an inverter board?

EDIT: I found this photo of a chassis with an inverter board installed...the red wire running to the bottom of the photo is the 16VDC line (as seen in another photo)...it APPEARS that it hits the chassis where I have circled in yellow?   

EDIT #2: Another shot found...when I pull my chassis today I may be able to identify this elusive friggin' "AS" location.

[Kevin Mullins]

Thought I'd bump this up to see if anyone can get a decent pic of the AS spot on the main chassis for the inverter power supply.

[2600]

Here is a better shot.  STill not great, but best I could currently do.

The hole is write next to where it says D214/R232

[Kevin Mullins]

Cool
Looks like I was totally in the wrong area on my earlier guesses.

And now of course there's even more questions...... because if you find that area on my chassis, there are parts on mine where they are missing on yours.
(mine does not originally have the power lead)

I'll try to take a better pic of that area on my chassis as well to compare.

[2600]

Odd question, but have you actually used your chassis?

The 20EZ is often referred to as the Nintendo Monitor, but other companies did use them.  Those companies had the section of the board populated so that you did not have to supply inverted video.  I believe Bob Roberts and Zanen? offer a kit so that you can add the missing parts to the "Nintendo" 20EZ so that you don't have to supply the inverted video as well.

[Kevin Mullins]

Yeah, mine was working until the flyback went out a couple years ago. It came out of a Nintendo cabinet that had been poorly jammatized . And yes, the colors were inverted /wrong. That area you mentioned is not populated on mine, nor did it have an inverter board or the power lead at all on it. I just keep it around now to look at when helping others out. Mine was an early version of the Sanyo 20EZ's.
(my cabinet is red) 

For those that want the parts list to convert there's to the "standard" non-inverted version without using the inverter board:

To convert the Sanyo monitor to accept normal, positive video:
1. Remove the wire jumpers that have been installed in place of
transistors TR201, TR202, TR203.
2. Remove R213, R214, R215.
3. Install the following components:
   a. R201, R202, R203   100K
   b. R210, R211, R212   100K
   c. R213, R214, R215   820 ohm
   d. R217, R218, R219   560 ohm
   e. TR201, TR202, TR203   2SC1815 or equiv.
   f. C202            220uf 16V
   g. D210            1N4004

Keep in mind though that if you do the component conversion it will no longer work with the older Nintendo boards at all.
And the inverter board doesn't work the other way around for that.

[2600]

I would of thought the inverter would still worked fine.  Do you know why it doesn't?

[Kevin Mullins]

I haven't found the best way to describe that part yet......

When the chassis was modified from a standard monitor to work directly with Nintendo games there were components on the main chassis removed. The inverter board in effect replaces those missing components in order to allow it work "normally". When the inverter board is found in a Nintendo machine, even if connected, it basically bypasses all the circuitry on the inverter board and the video signal goes straight to the main chassis which has been modified to accept the inverted Nintendo signal.

So if you go and replace the missing components on the main chassis then it will once again be a standard monitor. It will not accept the inverted Nintendo video signal directly. If you connect a Nintendo game to the inverter board as you normally would then the colors would be wrong because that connection bypasses the inverter circuitry and goes straight to the main chassis. (which now only accepts a standard signal)

And quite honestly, I don't know what the effect would be if you then connected it the "JAMMA" / INVERT OUT side of the inverter board, because this would in all essence be doubling the circuitry. (keep in mind that side does nothing without power)

Make any sense ??   

[2600]

I hear what you are saying, but in principle I don't see why it won't work.  I haven't looked at the schematic and examined it in great detail to answer this question, but it's an inverting amplifier.  You should be able to hook two inverter boards in series together and the output should be near the same signal as the input.  That's why I was wondering if you knew the specific reason why it wouldn't work. 

[Kevin Mullins]

I haven't picked it apart either and so just assumed there would be issues with trying to run it that way. When I first got into researching the Sanyo's and the "inverter" board it was more for being able to explain how it's supposed to work and what does what and why. Especially since there are a couple variations out there as to some chassis have this or that but not this or that, etc. (meaning power lead and or inverter board)
I'd be curious to to know for sure if running the circuits in series would indeed work.

But my first question for not having looked that deep into it is:
"Why didn't Sanyo just do that in the first place."

Why go through the trouble of modifying the main chassis if all they needed to do was add the inverter board and run it "backwards" per say from what they do now.