First off I'm still a beginner. I managed to find a Devil's Riders at a garage sale about two years ago that had a bad bridge rectifier on the power supply board. I replaced it and have enjoyed many games since that, but haven't played it in over 6 months now.
Well, I flipped it on tonight and quickly noticed I didn't have any sound? Still I played a game and left the room for maybe 5 minutes. When I came back into the room I noticed that awful smell of electrical burning or at least getting hot. I shut it down and looked in the back box and nothing looked charred with just a quick look over. I powered it up again and noticed that the sound board LED powers on when I turn the machine on but I only get a little tick or a pop from the speakers and then it shuts off.
Also the heat sink that I had replaced the BR on years back was really warm? Still I'm not 100% positive that this is the source of the smoldering smell. I took it off and all four of my solder joints look fine from the bottom of the board.. I did use the heat sink compound on all three BR's when I replaced the sink too.
Anyone have any hints on where to start? I guess I should have replaced all three of the BR's when I had it off the 1st time. I guess if no one has any ideas I'll start there and replace all three , the older two and the newer one I did last time.
I attached a pic of the back of the board for what it's worth, but I don't know it might not even be the problem.?

Thanks for any help and tips on how to repair this myself, Bill

zacPS.jpg

It's pretty obvious that the bottom BR is the one I replaced.. My first solder job on a board and I haven't had to do any others since, so I'm still probably messy at it.

Edit: I'll test the voltages at the connector coming off the transformer in the morning, it's about 2 AM right now.. I need sleep

All power supply voltages test fine so I believe my problem is with the sound board. I went into the sound test and I hardly have any of the actual sounds. I have all the speech sounds but hardly any of the sounds for pop bumpers, roll overs etc.. I have a few like score/bonus count down but there are a lot not working?

Also I checked test 29 and I have it set to have both sound and speech ON

Yes I did, I believe the BR's came from Mouser.com or Jameco.com. Like I said it has been awhile since I did that repair and it worked fine for over a year that I know of. I've ruled out my previous repair.
I did recheck the PS board just to make sure it tested OK. I have all the proper voltages coming off the transformer at connector 1. They are a little higher than what is stated on the Zaccaria site ( e.g. Pins 1-2 should have 165VAC and it test at 181VAC on my machine) Also I tested all the Test Points and they all test good with the same characteristics of having a few volts higher than stated on the Zac site.

So I moved onto the Sound board, the Zacarria site says that "Electronic sound effects are generated via a GI AY-3-8910 and/or a 1408 DAC, and sampled speech clips are recorded in ROMs on the board played via a TMS5220 speech chip"

I quoted this because I'm guessing that the sound generator GI AY-3-8910 may be the problem since I don't have any of the electronic sounds and all the speech clips. Problem is I don't know how to test it to make sure.

The Devil Riders sound board does have a Test button. I disconnected the ribbon that goes to the CPU and push it and just like in game play all I get is the speech.. I get the same thing when I run the test through the programming feature with the button inside the coin door ( Test 29) It goes down a list and plays samples all the sounds of the game. There are 30 something test positions where it should play a sound and all I get is the speech and hardly any of the electronic sounds.

So basically I believe I am only getting sound from my ROM's and not the sound generator, but being new to all this I'm not sure how it works to even test it.

Here's a video of the test button on the sound board and the way the LED flashes. I hope you can see it. I did some annotations to show the ribbon to the CPU is disconnected, the flashing LED and how I get a few partial noises of the electronic sounds before it goes to the speech sounds

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I know it's hard to see and I'll do another video later, but it looks like the LED pauses on one of the test. Here is what the Zac site shows for what the flashes mean.

The LED flashes and their meanings:
Flash Test
1 CPU RAM tested OK
2 PIA 1 (IC15) - Sounds tested OK
3 PIA 2 (IC14) - Speech tested OK
4 Sound generator tested OK
5 Speech synthesizer tested OK

I'm thinking the pause is flash test 4 not passing or registering? Anyone have any clue?

Let me make sure I'm following you and you me. I only get the speech sounds and don't get any of the playfield(electronic) sounds.. I do get the electronic sound of the score being counted and that is about it as far as playfield.
Wish I had another to swap the board with but we know how that goes.. I'll switch ribbons and see if that helps. Thanks

I switched the ribbons between Driver board and Cpu with the one from Sound board to CPU. I didn't help.
I also posted another video of some game play. Hope this shows what sounds I am getting

The video is right side up but not in the preview

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Looks like both our machines use the same sound board, the 1B11136.
Like I said I'm just learning but did you read this part on the Zac site?

"I have seen a couple of 1B11136 sound boards with problems where the board still appears to work, but the sounds are wrong, missing, or are VERY faint when played. Some sounds may be ok, others very faint or distorted. This is caused by a failed or missing MF10 filter IC at location 2O on the board. This is because the 8910 sound generator has three output channels, all of which are used by the game. But, only two of the channels are fed through the MF10 filter. So, the sounds that are primarily channels "A" and "B" sound wrong, but sounds that are primarily channel "C" sound fine. Sounds produced via the 1408 DAC do not go through the MF10, so those will sound fine."

Ok so I keep reading the above quote from the Zaccaria site and then I found the Sound map for my game here http://www.zaccaria-pinball.com/gen2/index.html then go to Game Documentation for Devil Riders and then Sound Map

I hit the coin door sound test "self test 05".. I printed out the sound map for my Devil Riders and noticed that all the sounds that I do have are produced by 1408 DAC just like the above quote. If you look at the Sound Map again http://www.zaccaria-pinball.com/gen2/index.html you'll see that I have the sounds labeled "sound numbers" 03,09,10,16,18, and 19 out of the first 24 sounds tested.
Of the 24 sounds I do Not have they are produced by an AY-3-8910 Sound Generator but so are the sounds that do work after "Sound 25".. So that still leaves me a little confused

Hope that can be followed but I'm thinking I need a new "MF10 filter IC at location 2O" like stated in the Zacarria sites quote.

What do you all think?

Anyone know what the specs are for the "MF10 filter IC at location 2O" ?

I pulled the old one out ( luckily there is a socket at location 20) and it is a 10 pin IC with what looks like /88330 MF10CN on it but it's hard to read. I can't seem to Google much up on it, any idea?

I hope I'm right on this?
I did find that the Zaccaria site has Data Sheets for each board.. NICE ! David Gersic put a lot of work into that site.

Looks like a MF10 is a "Dual universal switched capacitor filter (sound filter)"

Thanks for the offer, but that's a drive. I just ordered a few MF10's, I really only needed the one but Jameco has a $10 min. order or they charge you $5 extra on S/H.. So instead of one MF10 for $11 I bought three for $15. I guess I'll stick them on the shelf?
I hope the MF10 solves it for me. I'll let you know what happens, hopefully it will help you out too.

I'll let you know. I want to get mine up and running before I get rid of anything.

Glad to hear you found and eliminated one problem board.

I had to laugh at myself earlier, I realized that I bought those MF10's off E-Bay and not from Jameco like I posted before . I had them in my cart on the Jameco site and had them at the "commit to buy" page on E-bay and could have sworn I bought from Jameco. I really don't know how I spaced who I bought them from but I did.
Anyways I bought 2 for $11.50 which is what one from Jameco would have cost.. E-Bay shipping will probably take a little longer because I sinned and didn't buy American. Haha, then again China is probably where Jameco gets them too

Am I missing something? On Devil Riders the sound setting is Setting 29.. You set it to "01" to have All Sounds and Sentences

I received the MF10CNN in the mail today. My Devil Riders already had a socket for IC 20 so I slipped in the new MF10 and now have All sounds.

No, the MF10 was bad at spot IC 20 of sound board 1B11136. It already had a socket installed so all I did was remove and replace the bad MF10 and I now have all the sounds back.. The MF10 has something to do with all the sounds that are not associated with the 1408 DAC

Here is the quote again from the Zaccaria page, my MF10 was there but malfunctioning

"I have seen a couple of 1B11136 sound boards with problems where the board still appears to work, but the sounds are wrong, missing, or are VERY faint when played. Some sounds may be ok, others very faint or distorted. This is caused by a failed or missing MF10 filter IC at location 2O on the board. This is because the 8910 sound generator has three output channels, all of which are used by the game. But, only two of the channels are fed through the MF10 filter. So, the sounds that are primarily channels "A" and "B" sound wrong, but sounds that are primarily channel "C" sound fine. Sounds produced via the 1408 DAC do not go through the MF10, so those will sound fine."

What game are you having probs with?

Looks like on the sound map all speech is from a 5220 speech chip. Have you tried replacing it? This is just something I found in the Zac pages Game Documentation pages

Looks like the upper right corner of the sound board. I think I see it labeled on the PDF on the Zaccaria site.. I'll try to attach it to this post, but I don't know if it will load being it's a PDF..

Beware I have no idea what I am doing. I'm just looking at the Zaccaria site and repeating what I'm reading and seeing there. I have a lot to learn about PCB boards and electronics in general. Just letting ya know, that I am guessing from the info on that site that it might be the 5220 chip..