Operation Wolf repair notes

Riptor

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Im in the process of repairing a few Op Wolf boardsets and figured I would throw some notes up for the archives.
Main board #1
Symptom: Board booted and played 100 percent but would fail after a few minutes. A black screen would appear with "C chip no response" error. Occasionally "tilt" would flash just prior to the c chip error. This error was consistent and would happen after around 3-5 minutes. Rebooting the board just brought the error back. Only after a cool down period of about 10 minutes would the board reboot.

Solution: Searched the web for any info on the C chip error but came up empty. I assumed it refers to a custom chip. Since I knew it was a thermal problem I started hitting all the customs, one at a time with freeze spray. When I hit the TC0070 RGB module the game went from the error screen to fully operating. Ok, yanked one off a thrashed parts board and swapped it out. Same deal! So I figured it was something in the area was also getting cooled. I was right but was really surprised what it was. The problem was a bad 12.00mhz crystal. The board has run several hours rock solid. I have seen bad crystals a couple times before but never one that would work until it warmed up.


Main board #2
Symptom: Board boots and plays but screen only displays a turquois color and white.

Solution: I immediatly started inspecting the area around the RGB module and noticed some dark spots on some traces. Yep, acid damage and this board does not have a battery. Probably was caused by soda spilled down the control panel or was stored on a shelf next to a board with a leaky battery. I see this occasionally on pac boards.
I start ohming out the pins using my parts board to compare and I found that almost half of the traces to the module are open. About an hour later I finished jumping all the traces and colors are now back to normal. Ok, so the board is still not fixed entirely. I coin up and it starts a game on its own. Great, stuck start input. I traced the signal all the way back to the custom which controls I/O and thats as far as I got. This might be a tough one to track down because of the custom but I do know the custom is good so its something before it. Probably some more ate up traces.....back on the shelf for another day.

Sound board #1

Symptom: Zero sound output from sound board.

Solution: Checked the reset and clock on Z80, cpu is running. Sound rom was active as well. Probed the ram chip and found some noisy lines. Replaced the ram and the board was back 100 percent.

Sound board #2
Ummm, I forget. I really need to start writing this stuff down! Anyways it was broke and now its not :)

Sound board repair / diagnose tip:
Got a bad amp or suspect you might? The sound board has two channels that output the same thing on both sides. The game only uses one channel. You can remove the 5 pin speaker connector from the sound board and move the wires to the other two pins. You will now be running off the unused channel.
 
That's some great info. I also have an OW and have some sound problems. It will play sound for a long time then either stop all together or stop after you get killed. Turn the power of and on them the sound is back.

I'm going to try moving the speaker to the other channel like you did.
 
Thanks for the post. I have 3 op wolf board sets and want to get 1 working since I have a couple guns and a cabinet that is in decent shape. 1 board is in bad shape. Missing chips, bad caps, etc. The second board is intact, but does not seem to do anything. The third has some obviously bad caps and used to boot and play, but has since stopped working. I've been looking for someone that can accurately test the boards and maybe get one set working but I can't seem to find anyone that works on them. Board repair is not something I have tried my hand at yet since I am somewhat of a beginner. Monitors, cp, wiring I can handle, but boards I outsource.
 
Riptor great effort putting these together

Should save some machines from the burn pile.

I've been working on my OW and will post some of my findings.

As the game does not have a gun self test, what I did is take a battery powered strobelight and masking taped off some of the window (so I could scope the opto board and not be blinded) and then taped the unit to the end of the barrel. This let me generate reference 'pulses'. Sort of a signal generator. :)

Note that the photo diode does not put out a constant voltage, it allows current to pass as light swings up and down into it. So you need to strobe to create pulses, you can not just shine a flashlight at it.

What I have learned is there are at least sightly different revisions of the TAITO board.

On one version of mine someone ECO'd in a second 1M ohm resistor in line with R3 making it a 2M ohm

On the other for some reason they did not solder C1 into the board but instead soldered it across IC1's legs between pins 2 and 6. The feed through holes where it goes still had the wavesolder in them. I'm guessing the component was missing on the build and instead of removing the board the just hacked it across the chip. I moved the cap back to where it belonged and socketed the two LM318D's

Using a scope on the non-ground side of D1 and using the homemade pulse generator I can see about a .5V positive pulse. I found that one of my two boards at least had a bad diode as the other one would not pulse at all. I put the good diode on the board that had the bad diode and I'm working out some problem around the LM318 now. Looks like the pulses off the diode are not making it to pin 2 of IC1.

Other things to do, so I put it away for the night. Swapping those little boards in and out to test is a pain. :(
 
I need your help. I have two boards that I think have sound problems. It plays everything for a mission or two then stops. Turn the game off and back on and it's fine for a few missions. However today it plays for 3 sec at the start of a mission then stops. Here is a link to the video.

http://youtu.be/iCFgEfyBEks

I change the speaker wire to the other channel and it does the same thing. x to n (trying to remember)

Thanks in advance.
 
Yeah, I tried that but it still cuts out during play. I'm looking a sound board wiring diagram online but no luck. I have two boards and the both do the same thing.
 
The sound board pinout is easy, its in the manual. I had to do a bit of searching to find the sound board schematics but I have them now. PM me your email address and I will send them.
 
A couple more repair notes...

Board was missing some sounds. Problem was a bad op-amp TL074 @ IC51. Your mileage may vary but I had issues when I socket these. Low volume, distortion, static etc.


I had a board that was a Japan version. There is a dip switch setting for english/japanese but that does not get rid of the 'japan only' warning on boot up. Swapping out rom B20 (IC29) with the english version will correct this.
 
Just got another one of these in today and got it up and running. The sound board was working but had the same exact problem listed above. Same sounds missing/faint and it was the op amp again.
The cpu board would sometimes boot but noticably more after it warmed up. Left it powered up for about 10 minutes and it started booting everytime but would reset when the trigger was pulled during a game. Started hitting chips with freeze spray and found the boot problem came back when in the area of the roms. Pulled the roms and they all verified. Swapped in another set one at a time and found the game ran perfect when rom 39 was changed. Burned a new rom for location 39 and the board is fixed. Swapped the suspect rom in several times and the problem followed consistently. Strange since it verified in the burner...oh well I have seen that before.
 
Gun problem: Not registering any hits.
One would assume this is a problem with the guns optic or aux power supply but not in this case. Since I was using a known working setup I assumed it was a wiring issue since this cabs wiring is a little hacked. Checked the wiring and found no shorts or broken wires. Swapped out the pcbs and it works. I need to look further into this when I get a chance. I narrowed the problem down to the bottom pcb but thats as far as I went. It could possibly be a bad custom chip because I recall one of these boards having the customs plugged in backwards when i got them.

I just got in another three main boards and six sound boards...more OW repair notes coming.
 
Here's another one.
Board worked but would start a game as soon as a credit is added. Probbing the start button circuit showed it was working correctly. I followed it from the edge connector all the way in to a custom chip. I was stumped at that point because I have no idea what the custom does or any info on it at all. Put it back on the pile.
Came back to this board because I was checking eproms since I found some other boards with mixed sets. Sure enough, one eprom on this board was from an alternate set. Changed that rom to the correct one and the start button issue is fixed! Its very strange that was the only issue I could see from having the wrong rom in it.
 
It seems that one of my problems is with the Roms and I don't know what version I have. This particular board has a single sip in ic81. Usually there is a sip (smaller) in locations ic79, ic80, and ic81. I put the Roms from that board into one that was dead and now I get the C chip not response error. I flipped the dip for diags. and get object ram bad, motion ram bad. That is some progress. I have found some more info on the sound board from our friends across the drink and wanted to post here.

http://www.ukvac.com/forum/another-operation-wolf-sound-issue_topic329532.html

Now I don't know how many different cabs are out there but the one pictured in the above link is different than mine.
 
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There are several different cabs. I saw a thread somewhere with pics of 3 or 4 different cabs. I think the US version looks the best.
Those three sips your talking about are the RGB circuit. I have one board with three on it and all the rest have the single sip in their place. The schematics show the three sips so that is likely an early version.
 
Riptor +1 to your rep....

The board with the c chip not response <love the wording> is the 12mhz crystal. I was pondering what all I have to move to get to the o-scope and decided to look at the clock signal with the logic probe. Pin 20 on ic75 was stuck low and that should be the clock. I taped the crystal and the probe flashed?? Well if I have my helper (wife) push on the top of the crystal I would get a signal on the pin and part indicated. I don't know what would have caused this but I know the crystal needs to be replace or maybe glued down to pcb lol. Maybe I will glue a sinker to the top of it.

If it was not for Riptor finding the problem in his first post I would not have looked at this for some time. I had no clue what the C chip was or where it was located. This has advanced my project quite a bit.
 
I believe you'll also get the C-Chip Not Response error if a coin input is stuck, might be worth taking a look at as well.
 
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