Operation Wolf Ram errors

ManiN

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So I have an op wolf that has 2 errors when I turn on the service dip switch.

SCREEN RAM BAD
OBJECT RAM BAD

Anybody know of a reference that I can use to help identify where to start looking for these bad rams? The schematics aren't this specific, or maybe I am not recognizing things right.

I also had garbled sound effects as well. The music is fine, but the sound effects were all garble and then they finally stopped all together. Maybe the MB3735? Maybe a DAC? After it died, you can still hear the sounds very very faintly. Makes me think the MB3735 is dead. Not sure which is which on the board yet.

Any insight?
 
So I have an op wolf that has 2 errors when I turn on the service dip switch.

SCREEN RAM BAD
OBJECT RAM BAD

Anybody know of a reference that I can use to help identify where to start looking for these bad rams? The schematics aren't this specific, or maybe I am not recognizing things right.

I also had garbled sound effects as well. The music is fine, but the sound effects were all garble and then they finally stopped all together. Maybe the MB3735? Maybe a DAC? After it died, you can still hear the sounds very very faintly. Makes me think the MB3735 is dead. Not sure which is which on the board yet.

Any insight?

Sounds to me like it may be the sound amp or a cap going bad. I'll look at mine later tonight and take some pics. I can probably post the pics tomorrow.
 
Sounds to me like it may be the sound amp or a cap going bad. I'll look at mine later tonight and take some pics. I can probably post the pics tomorrow.

Bad amp or amp section cap isnt going to garble the sounds, it will cause amplification errors, or distortion.

The 2018 SRAM on these boards is a common source of failure, I would start there, there is one on the audio board, which is almost certainly not tested by the bootup sequence as the main CPU doesnt have access to it.
 
I whipped out the Blue ESR and found all the caps in the audio section were ~double the value they should be. I recapped that, and will move to the ram. I'll be able to test this weekend.
 
Out of town, plan to get on it this coming weekend.

I have a cab and working set so if you need values, from the board, let me know. I have about 5 sound boards and 4 cpu boards that all need some kind of repair so I will be working on this game quite a bit.
 
Ok, so life is a bit back to normal... For the moment

I recapped the sound and the situation is the same. Same goes for the ram errors. Additionally, the gun doesn't vibrate or register shots. I re-flowed the light board in the gun and tested the motor which does work when voltage is applied. Makes me think the board isn't giving a signal.

I see there was no pics posted, so here is what we see:
 

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Having quite the experience with this game, I suggest cleaning the jamma fingers on the board with an eraser and double check the 13+v at the auxiliary board. That is where the gun gets its voltages from for the motor. This is a good starting point and got my game going when I was having problems.

Good luck.
 
After having multiple issues with sound and gun not registering I ended up changing the big cap on the aux board and it solved all my problems. This game loves correct voltage!!
 
Having quite the experience with this game, I suggest cleaning the jamma fingers on the board with an eraser and double check the 13+v at the auxiliary board. That is where the gun gets its voltages from for the motor. This is a good starting point and got my game going when I was having problems.

Good luck.

I'll have to look at this closer, I had issues with a weak connection on the edge connector not allowing video unless I squeezed it together for better contact.
 
After having multiple issues with sound and gun not registering I ended up changing the big cap on the aux board and it solved all my problems. This game loves correct voltage!!

I checked this cap with an ESR meter, but will look again as that was a while ago. Dialed the 5V at the chips in pretty well, so I don't think power is horrible. I need to probe each chip in case there is a loss at sporadic places.
 
I checked the voltage coming out of the aux. board and it's in fact less than -13v, more like -11.5-12v or so. I changed the big cap (4700uf) and little cap (100uf, I think...) with no changes. Issues with the transformer?

As far as the sound goes, I noticed it will play the garbled sound effects (music is still perfect), then it dies out over time. I replaced the caps on the board, so I don't think it's them. I also see arcing on the heat sink of the bad channel (sound effects). This makes me wonder if it was shorted out from a coin falling on it. I read that many boards suffered from shorts due to coins falling through the gun mount and in top of the board.

Poking around I noticed a discrepancy in the PAL16L8s. I swapped them and the game wouldn't work at all, and when swapped back, it was fine. I probed them and found some ports on one putting out solid HI in lieu of a square wave or whatnot like the other. Bad maybe?
 
I'm reading the pals are programmable, so maybe that's why there was discrepancies? I hope, custom ICs are a pain.
 
I'm reading the pals are programmable, so maybe that's why there was discrepancies? I hope, custom ICs are a pain.

I am working on some kind of solution to socket and test the custom sip. I have not made much FORWARD progress on this but with 5 non working sets, I need to do something.

Not all sound problems are the sound board. I have one sound board that will not work with any other board except the working cpu board and then it will only play the music. No shots, no voices, just music.
 
The The sound effects are there, they are just distorted and slowly go away as the machine heats up... Totally would think caps due to heat, but I already did those. Working on a new volume pot right now.
 
The The sound effects are there, they are just distorted and slowly go away as the machine heats up... Totally would think caps due to heat, but I already did those. Working on a new volume pot right now.

Check the dac I think it is a ym3012 It is right near the bigger Yamaha ym2151 chip.
 
Some success! I was working on the gun and traced the lack of 12V back to the board. On the 4 pin connector labeled 'M', I checked the voltages and noticed there was in fact 12V, but on a pin where there was no wire in the harness... I grabbed the manual and verified the connection on my game was wrong. I took a leap of faith and re-arranged the pins according to the manual and.... *insert shake your booty song* "shake shake shake"! It works! The only thing I can think is that the previous owner didn't like the noise of the gun so they changed the pins to allow firing, but not motor action.

Additionally, the shots didn't register either. After reading on how important brightness is, I decided to work on the dim k4900 I am using. I recapped and re-flowed etc. with no improvement. I finally decided to swap the board into a monitor that had a bad board but assumed good tube. This worked and I had a nice bright screen. I put this into the cab and shots registered! I actually played the game for the first time! (since owning this one) Of course the video errors are still there, but I could still wax the enemy haha. Now I just need to dial in those sound and video issues. I would have ordered ram and the YM chips by now, but a buddy said I could test with some of his extra boards once he finds them, so I'll hold for that.
 
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Some success! I was working on the gun and traced the lack of 12V back to the board. On the 4 pin connector labeled 'M', I checked the voltages and noticed there was in fact 12V, but on a pin where there was no wire in the harness... I grabbed the manual and verified the connection on my game was wrong. I took a leap of faith and re-arranged the pins according to the manual and.... *insert shake your booty song* "shake shake shake"! It works! The only thing I can think is that the previous owner didn't like the noise of the gun so they changed the pins to allow firing, but not motor action.

Additionally, the shots didn't register either. After reading on how important brightness is, I decided to work on the dim k4900 I am using. I recapped and re-flowed etc. with no improvement. I finally decided to swap the board into a monitor that had a bad board but assumed good tube. This worked and I had a nice bright screen. I put this into the cab and shots registered! I actually played the game for the first time! (since owning this one) Of course the video errors are still there, but I could still wax the enemy haha. Now I just need to dial in those sound and video issues. I would have ordered ram and the YM chips by now, but a buddy said I could test with some of his extra boards once he finds them, so I'll hold for that.

I have a few of the ym3012 and the Yamaha 2151 I think they are, I could send you one of each as I don't want to see a board torn apart for them chips. I am out of town right now but when I get back and settled back in I would be more than happy to send them out.
 
That'd be sweet man! I forgot to mention, I actually swapped the amps to see if the error would swap as well, but it didn't, this verifies both amps are fine and that I think you are right in that it's either the YM3012 DAC or the YM2151 for sound.
 
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