Black Knight No Sound Help!

[time4akshun]

Guys,

I picked up the a nice Black Knight back in 2004 that was working great. I made the massive mistake of connecting the black and white molexs together and fried the sucker.

Sent the boards out to get fixed and I have Black Knight again. Problem is, no sound.

Looked at the board and see the following problems:

1. Jumper on Sound PCB is disconnected (Not sure if ever was even when was working)
2. Sound PCB connector looks a bit burnt (Not sure if from what I did)
3. Red power cable is disconnected from bottom of backglass cab (Rest of game works fine, not sure if related or where to resolder)

Take a look at the pics and let me know if any of the symptoms seem related to my no sound issue. If any thoughts on which to address would be helpful. I'm a vid pro but pin noob.

Thanks in advance!!

Gil

 

[Silverunicorn]

Hi Gil -


Are you sure all the connectors are on the board? Not trying to insult you, just trying the easy stuff first

Also there is a potentiometer that balances the sounds and speech. Make sure thet is not turned all the way one way or the other as well. Another question - If you press the test button on the sound board, do you get anything then, or is there just not sound altogether?

The broken jumper is a bit odd to me. I don't have anything on my BK where your broken jumper is (I did not pull the sound board, it IS possible that it may be jumpered on the back, but I am not sure:

The red wire that is in the backbox also is strange to me. I am assuming this is in the bottom right hand side of the backbox, by the blue cap? Mine does not have a setup like that either. Let me ask you this - if you follow that wire, where does it go?

This is what I have in my backbox. Let me kow if you need larger photos of anything and I can get them for you.

As far as the burnt looking connector, none of the heat marks look to be at the areas where the wires go. Not sure if that would be related to your issues or not (I would lean toward not).

Let me tell you, about the hooking the connectors up wrong - Been there, done that! You're not the first one to make that mistake.


Chris

 

[HHaase]

Ok, lets see where I can help out here.

That red/orange wire you have..... looks like yours has the System 6 style power supply, and that's the GI lighting relay in that photo. The busted off wire should be soldered onto the top-left connector on that relay. My guess is your GI lighting never flashes off and on, which is a shame as it's a big part of the light show on Black Knight. Particularly with multiball.

That fried connector. That's your power input into the sound board. Cut that beast off of there and properly crimp on a new one. Always splurge for the trifurcon style pins on these machines, they are a huge improvement. It may, or may not, be the cause of your problem. Make sure to inspect the connector on the board too, it may need to be re-soldered due to cracked connectors on the board. Get used to doing this style connector, you'll be doing a lot of them over time. Anytime you have a problem, if it's got the original connector still on there you'll want to replace it as one of the first things you do. They fail... a lot.

The broken jumper wire.... That's "W-1". You only need to install that if you are using the sound board without a speech board. It makes me think that the sound board problem existed before you had the machine, and that the previous owner did that to try and diagnose it. You can just clip the rest of it off of there if you want, you don't need it.

Oh, and also make sure to use ALL the mounting screws for the sound and speech boards, and have them down nice and snug. Otherwise you get a lot of scratchy noises coming through the speaker, as the board is dependent on the metal frames in the backbox for proper grounding.

-Hans

 

[Silverunicorn]

Ok, lets see where I can help out here.

-Hans

Um yeah. Listen to Hans. He's ALOT smarter than me

Did not even occur to me that you could run the System 6 PS in a System 7. Duh.

Chris

 

[time4akshun]

Guys. Fantastic responses and thanks so much for taking the pics! Your board looks much cleaner than mine. Will attempt the recommendations. Also picked up a PinballPCB.com sound board replacement as a back up.

Will let you know!! Thanks for making me not feel like an idiot for the back connector flub!!

Time

 

[HHaase]

Oh, you've got a Kohut board too? Just use the replacement, they've got a fantastic reputation. Will sound better too with all the new caps in it.

-Hans

 

[Silverunicorn]

Thanks for making me not feel like an idiot for the back connector flub!!

I would never fault someone for that. I have been there, and know the agony it causes. I felt like such an idiot when I did it, but a guy that I respect fully told me he had done the same thing when he bought a BK in 1980 to put on route. He did the same thing 20 years later as well.


It happens. Learn from it, or do what I did and label the plugs

My latest BK has different colored plugs now (I think they changed this in the later runs), so one is whire and pne is black. They are still keyed the same though

Hope you can get the sound resolved.

Chris

 

[time4akshun]

UPDATE:

1. So the red/brown wire was reconnected/solder to the relay Hans mentioned and I now have GI lighting action. Thanks Hans!!

2. Broken W1 jumper fully removed. No impact of course but done.

3. I swapped my original Sound PCB with the Kohout replacement and was hoping for magic but NOTHING. I'm sure the Kohout PCB is working so I am now left with the fact that my burnt connector might be the problem here. Just ordered a replacement to re-crimp a new one from pinball pcb.com also per Hans guidance.

Will report back when this is done. Still searching for sound on Black Knight.

One other possibility: I had heard on my original post when I put the 2 wrong molex connectors together that originally caused my issues that the AMP IC was blown for someone else this happened to... Is the AMP IC on the sound board or somewhere else? Another culprit?

Thanks guys! Will post after connector swap is done.

Gil

 

[Lindsey]

I edited this thing a lot.

3. I swapped my original Sound PCB with the Kohout replacement and was hoping for magic but NOTHING. I'm sure the Kohout PCB is working so I am now left with the fact that my burnt connector might be the problem here. Just ordered a replacement to re-crimp a new one from pinball pcb.com also per Hans guidance.

What happens when you press the test button on the sound board? That should tell you if it's a sound board or MPU problem. Or at least narrow it down. If you get sound you can suspect a possible MPU problem like a blown PIA. If you get no sound start by checking the power supply section of the sound board and go from there. The fact that what should be a known good sound board doesn't work makes me think it could be an MPU problem. You should also check the speaker just to be sure it's working.

I would pull the MPU and sound board and go through both with test ROMs. That's the best solution.

EDIT:
I wrote an article about the older generation sound board. Most of it should apply to the newer generation. Hooking it up to power and a speaker and manually testing the sounds will be the same:

http://warpzonearcade.com/?p=365

One other possibility: I had heard on my original post when I put the 2 wrong molex connectors together that originally caused my issues that the AMP IC was blown for someone else this happened to... Is the AMP IC on the sound board or somewhere else? Another culprit?

The audio amp is on the sound board so I would expect the other sound board to work if that were the problem. Unless both are now blown up

Testing the boards out of the game would be ideal.

 

[HHaase]

D'oh, I can't believe I forgot that System 7's moved to a dedicated sound PIA.

But Lindesy's totally correct, start with the self-test on the sound board first. That will really help isolate where to start looking for the problem. The sound boards have their own complete CPU section on them, and that sound test should work even if you have no main CPU board installed in the machine.

If both boards don't work with the sound test, then it's either going to be power or a speaker/volume knob issue (Unless you blew out the new board, and I highly doubt this)

-Hans

 

[time4akshun]

OK. So the connector has now been recrimped. Still no sound...

Going after the speaker next, then the volume control, then the power supply, then insane... If no power is headed to the sound board I'll need PS help for sure.

Keep you posted. Vids we so much easier!!

Time

 

[time4akshun]

Power is confirmed to the sound PCB so the power supply is fine and the new Kohout PCB is fine. 18volts to the fuses. Speaker swap next...

 

[time4akshun]

So working with Jeff Kohout on some troubleshooting. Speaker showed up and Jeff told me to connect the spear wires to pin 1 and 4 on the speaker 4 pin connector. I still don't get sound just a squeal to the speakers both in the Kohout board diag mode and regular play mode.

Sending back the Sound PCB to Kohout for a replacement as a last ditch option.

Time

 

[time4akshun]

Closing the loop on this thread. My dead Black Knight is now alive for first time since 2005!

The bad connector pairing blew my speaker,volume control, and main pcb primarily. Power pcb and sound pcb were fine.

Replace main pcb via Kohout and speaker via Amazon. Jeff Kohout from pinball pcb.com was a tremendous help during all of this. He even helped me with items that I didn't purchase from him!

He has a customer for life and BK has a player for life. Happy day!

Time

 

[time4akshun]

Also big thanks to Hans and SilverUnicorn!