My Space Emcounters display is no longer solid white ...

[unclet]

I found a missing 1.5Amp monitor fuse and once I replaced this, then the monitor tube glows when I turn on the machine, however, the image on the monitor screen is simply a solid whitish color (see photo).

[unclet]

Here is what the monitor display looked like when the previous owner had this cabinet (before I picked it up) ..... something must of gone wrong when transporting the game to my home:


NOTE: Notice the lights work in this picture, although not in my picture posted above........ any ideas?

[Ken Layton]

Looks like power supply problems, likely on the 12 volt line since your lights are affected too. The power supply circuit board may need rebuilding (capacitors and resoldering bad solder joints). Your game is of the age where the fuseholders in the bottom of the cabinet may be corroded/tarnished/cracked/metal fatigued and need to be replaced.

[unclet]

The fuses next to the isolation transfomer (on the floor) have continuity.  The monitor fuses (ie: .75Amp and 1.5Amp fuses) also have continuity.

I referenced the following PDF file when testing my power supply:

http://www.arcadedocs.com/vidmanuals/S/SpaceEncounters.pdf

I was able to back-probe the molex connector on the white power supply board (see photo) and verify the following:

The V-Ac input readings I received are as follows:

White/Green wire and Yellow/Black wire = 13.9V (which is ~12.0V)

Yellow wire and Black wire = 19.0V (which is ~16.5V)
Yellow wire and  Orange/Black = 10.3V (which is ~9.0V)
Yellow wire and Red/White wire = 10.3V (which is ~9.0V)
Yellow wire and Grey wire = 19.0V (which is ~16.5V)


The V-Dc readings I received are as folllows:

Orange/Red wire and White wire = 5.0V (exact)
Orange/Red wire and White/Brown wire = 13.0V (which is ~12V)
Orange/Red wire and Black/Green wire = -5.0V (exact)

   
I guess you are saying I should follow the 12V-Dc line to see if there is a break somewhere.    Any recommendations on where to start doing this?

IMPORTANT FINDING?: I verified my power supply board still was producing the 5V, 12V and -5V as stated above ....  and it does as long as the "Main PCB Plug" (see labelled photo) IS NOT plugged into the Main PCB.   

When the "Main PCB Plug" IS plugged into the Main PCB, I get the following readings:

Orange/Red wire and White wire = 5.0V-Dc
Orange/Red wire and White/Brown wire = -56V-Dc
Orange/Red wire and Black/Green wire = -110V-Dc

Is this change in the V-Dc readings explainable when the plug is plugged into the board?

[Ken Layton]

Yuch that power supply board looks horrible. It still has the original capacitors on it (the largest one appears to be leaking). The two main diodes have obviously gotten hot enough to discolor the circuit board and probably have bad solder. I suggest resoldering the plug in connnector's pins on the circuit board.

Get a rebuild kit for this board or send it out for repair.

[unclet]

I have two other power supply boards like this one....... maybe I will just use another one. 

How can you tell that a capacitor is leaking?

Also, do I need a rebuild kit if I verified the 5V, -5V and 12V lines are being produced by the power supply (as detailed in my previous post)?

[Ken Layton]

Those Mexican made caps always leak. Look at the end of it. I see a bulge where it's blowing out. All those caps are original. Capacitors do not get better with age.

Just because you show the voltage output from the supply does not mean it's clean output. There's likely noise/surges occuring that your meter just can't read.

That plug in connector on the board is well known for developing bad solder joints.

[unclet]

Ok, I am an idiot ..... I had the main PCB wiring harness connector on backwards ....

[dabone]

Thats a black and white game right???

Sub a vcr signal for the game signal to test your monitor, it's basically a black and white tv with composite input.

Most likely your boards will need repair.
(And the power supply rebuilt)

Have you asked around on rgvac for someone that repairs these boards?


Later,
dabone

[unclet]

Yes it is a black and white TV..... but I have no idea what you mean by "Sub a VCR signal for the game signal to test your monitor".  I would assume you mean to simply hook up my VCR output to the monitor, but I am not sure how to go about doing this.

I would have video and audio wires coming out of the VCR (yellow=video, red/white=audio), but where do I attach these to the monitor .... assuming I would use my alligator clip here ... but where? 

Picture would be great ... :>)   

PS:  Any chance that if I do this wrong, then my VCR will fry?

[dabone]

Video only, no sound.

Yellow wire, on a rca connector the center is the signal and the shield is gnd.

A pic of your monitor board would help greatly.


And no if you hook it up right you won't damage a thing.


Later,
dabone

[unclet]

Here are some pics of the monitor board ..... is this what you wanted?

[dabone]

ok, whats the model number??

(Can't read it in your pics.)


Later,
dabone

[unclet]

Here is a pic with all the numbers on it:

[unclet]

It was mentioned that getting a rebuild kit would be helpful for my power supply.   What parts on the power supply would need to be rebuilt to consider this a nice working power supply? 

Is there a kit which has everything I need in it already .... if so, where do I purchase this rebuild kit?

Also, I had some more luck on the machine today.  I switched out the sound PCB with a nice clean looking one I had as an extra.   I also noticed that the DIP switches on the game logic PCB (ie: daughter board) were set to display the cross-hatch pattern, so I switched the DIP switches 5 and 6 to be ON (ie: BONUS is ON now) instead.  Now when powering up the cabinet, my monitor display now looks like the picture below.  I also could hear spit-fire noises coming from the speaker like someone firing a kiddie sounding machine gun toy.  Also, you can see that the little light bulbs under the monitor came on as well.  I was very happy.   However, I decided to test the other two extra sound board PCBs which I have and decided to take notes on what various changes were observed.  Anyway, the sound PCB I switched to originally seemed to be the best, so I decided to put that one back in.   However, after replacing the sound PCB the final time, I then powered up the cabinet to rejoice at the little lights one last time before calling it a night, however, the lights now do not come on anymore.  What could cause the lights not to come on anymore, when 10 minutes earlier they were bright with light?  I also noticed I was no longer hearing any sound from the speaker anymore.  I still have the same image shown in the pic below though ..... at least that is better than seeing a white screen   

I wonder if it is because the power supply main diodes were getiting hot again and thus causing my problems.   I will try to power up the cabinet tomorrow morning after everything cools down nicely and see what happens.....

Any ideas on what to do now?