Operation Wolf White Screen

starfighter2

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I was given 6 operation wolf boards. One displays bad object and display rams. I can fix that one, 5 of them have a white screens and one had bars that show then change to a different set of bars. some of the white screens have one or two blak highlight bars like there is text in them but cannot read any text. all of them where on the text setting on the dip switch.

Anyone see this before and have any ideas as to what to look at. I looked around on the forum but did not see anyone have this issue.
 
First thing to check is the voltages at the chips then check the clock signals to the cpu. If it is getting a clock signal then you need to check the enable lines and watchdog.

What type of CPU chip(s) does that board have?

It sounds to me like you are not even getting the board to start.
 
I a m fairly new to debugging boards. Have done a bunch with monitors. is there a resource that helps explain how to test these things and what to use. I have an scope and meter.
i.e. how to test and expected result. Any assitance would be greatly apriciated.

Example, when testing the crystal which end do you test. do you use a meter, scope, or some other probe. should I see a pulse, always on or off?

I would agree that he board is not booting. I have several boards so this is a great way to get into understanding how to fix games boards, just looking for the education part.
 
I a m fairly new to debugging boards. Have done a bunch with monitors. is there a resource that helps explain how to test these things and what to use. I have an scope and meter.
i.e. how to test and expected result. Any assitance would be greatly apriciated.

Example, when testing the crystal which end do you test. do you use a meter, scope, or some other probe. should I see a pulse, always on or off?

I would agree that he board is not booting. I have several boards so this is a great way to get into understanding how to fix games boards, just looking for the education part.

First things first.
You need to understand a few things first. Spend a little bit of time reading the sticky

http://forums.arcade-museum.com/showthread.php?t=177192



Epically post number 7 cpu 101. You allways want to test power and this is in the sticky also. Then you want to test a few things.

To test the crystal, there is usually a small metal can type thing on the board with numbers on the top. Not all boards have them so you need a schematic of the board to B sure as some are internal. You can just put power to logic probe and probe either side of the crystal to see if there is a pulse. You should just see a flashing light and no sound (no logic low or no logic high). Some probes may be different but you should still see some kind of pulse on the logic probe. You scope should show a steady clean signal.



My z80 cpu boards have them (metal can crystal) and the clock signal (sig) is on pin 6 of them (z80). I have had some that had no clock and followed the circuit back to a custom chip. The chip, a 07xx, had good input but grounded all outputs. This is very bad as the clock sig. is like the starter in your car.


The scope will be of better use after you get the "car started". The first thing that needs to happen!

I am not familiar with that board set and I will look for schematics. I am on dial up so finding/downloading them takes some time.


Read this link also it will give you a place to start and additional info.


http://forums.arcade-museum.com/showthread.php?t=9959
 
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I don't have a logic probe, but it has been on my list to get, Do you have any recommenations?

In the mean time I'll look over the schmetics, and the links you game me.

Thanks again for your help
 
I don't have a logic probe, but it has been on my list to get, Do you have any recommenations?

In the mean time I'll look over the schmetics, and the links you game me.

Thanks again for your help

I have made one but I finally did break down and bought one. This one is not the best but it does work well and has audio so you can concentrate on what you are doing.

http://www.ebay.com/itm/400223442078?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

It is like 22 dollars including shipping and it is in FL so you should get it soon.

If you have the schematics or a link to them I would like to have a look at em. I have only found the basic wiring for the cabinet and not the pcb.

bill

This thread shows how to use a logic probe on ic chips.

http://forums.arcade-museum.com/showthread.php?t=192913&highlight=testing+star+wars
 
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Done, Purchased. I have the schmatics and will look them over, there are several version. Some with more information that others. Non of them look as good as say a pac-man or galaxian schmetic, but I think that is all that is out there. I'll start to look over them this weekend.
 
I can't really offer insight to your repair, but I suggest get a *working* board for a spare/backup...

Operation Wolf boardsets have to be in the top 5 in most problematic boardsets! My buddy has an Op Wolf (and also 8 boardsets), seven of those are nonworking! I tried to figure out a issue w/ one (same issue you have), never did find it!

I don't know what it is w/ these (cheap compenents?) Bad ram? Who knows?
But, as the previous poster said - Logic probe is an *absolute* must if you want to work on these! And make sure it has audio capabilities....
 
I don't have a logic probe, but it has been on my list to get, Do you have any recommenations?

In the mean time I'll look over the schmetics, and the links you game me.

Thanks again for your help

If you have a link to the schematics I may be needing them soon. I am seriously considering buying the lot of Operation Wolf boards from TNT Amusements. There is like 10 of these boards available and they don't work. Out of that set, I should be able to get one going.

I just bought 7 1/2 of the board sets from TNT Amusements. I bought every one they had so I should be able to help you out, or you should be able to help me out.
 
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Ok I finally got my crap together and put together a test environemnt, got a logic prope and started testing.

1. With the roms I could test with my programmer, all the 27512 roms (5)tested fine (i.e. got the same checksum as the rom in mame).

2. I then started testing the reset on the 68000 cpu pin 18 on the main board. I get a low then High which from my understanding is a good thing (tell me if Im incorrect please).

BUT, if I keep it there after 30 seconds it will then go low then high again and continue to do that over and over. Does that mean that the cpu is resetting?

If so what is my next step. Do I test the crystal? if so How? The only legs I can see are on the solder side and there are 4 post. Again, Trying to learn and have 5 boards to play with. Thanks for all of your help.
 
It means the board is trying resetting the CPU as it sees it has locked up, this is the "watchdog" circuit in action, it is a timer that is constantly reset by system activity. If the board locks up then the activity stops, the timer expires and the watchdog "barks" ie bounces the reset pin on the CPU/CPUs. Primarily it is there to stop a cabinet sitting in a crashed state for hours due to some flicker on the mains supply, a crashed cab earns no money and risks burning whatever junk is on the screen into the CRT. Of course with board faults the watchdog will just bark for eternity.

It won't be the crystal, if the soldering on the pins is good and it usually is, if the crystal was bad you would get absolutely no activity on the board. Poke your logic probe at the clock pin on the CPU, if you see activity you can pretty much rule out the crystal. If the clock is active then there are other candidates that are 100s times more likely than something wrong with the clock signal itself.

You almost certainly have a TTL logic or RAM fault, I would start by looking at the RAM next to the 68000 CPU, that is usually the main culprit for boards that will not boot, assuming you have ruled out power issues, board interconnects and physical damage of course.

Am in need of an Op Wolf board for my cabinet - care to donate one to a good cause? :)
 
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Sorry to hijack the thread.

I have one that you are welcome to have Womble. Has video but bad sound. I have 3 of them arriving in a week or so. One is suppose to be working 100%, the other 2 are untested. Hoping for the best but not being too hopeful after reading how problematic these boards are.
 
Wow - thanks Mr Eagle, have dropped you a PM.

I picked up an Australian Operation Wolf cab a week ago and was a bit annoyed to find it had a massive bootleg version in there. By the looks of it it is the Operation Bear board with Op Wolf ROMs on it so it behaves like an original. The original board mount holes are there so I assume the original died while it was still earning money.
 
Yes the clock should pulse, very very rapidly and continuously.

As for testing RAM - see the sticky thread on board repair.

http://forums.arcade-museum.com/showthread.php?t=177192

There is no conclusive way to test them on the board, for 100% diagnosis you have to desolder them and test them in an external tester, but you can get clues from the pins, although without a scope it is a bit hit and miss.
 
This MAY be of use - I recently worked on a Bubble Bobble that had a white screen (the text could be seen very, very faintly in black).

Turns out that the -5 volt connection was poor, and fixing that at least gave a decent image.

Now I know that Op Wolf isn't exactly the same hardware as Bubble Bobble, but there are similarities AND it uses the same connectors for power, etc.

Not saying this is the problem here, but it may be the cause of the white screen.
 
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