Repairing The Hum On a 1987 Space Station Pinball Machine - Comparing The Williams Sound Boards 

little system 11 sound info: "System 11 sound used 'FM sound', which is generated from the YM2151 8-voice FM synthesizer chip. Digital sound data from the YM2151 is converted into an analog signal in the YM3012 DAC chip. A preamp MC1458 chip pre-amplifies this analog signal before it is sent to the mixer and final amplifier. System11 usually assigned a pair of FM-voices for an instrument. This is what made system11 FM-synthesis stand out in sound quality and innovation. The synthesizer was also capable of making noise sounds and this was used for most of the cymbal and hi-hat sounds. Williams used the term 'general sound' for any sound created by the MC1408 DAC chip. Sampled sounds, such as drums, are processed through the DAC. These are all 8-bit samples stored in ROM. Algorithm-based sounds are also processed through the DAC. These sounds are created by software algorithms. They are played monophonically (only one sound can play at one time), and are easily distinguished this way. Algorithm-based sound was used widely in Williams system 3 through 11B games, and it was stopped starting with system 11C games. All speech is generated from the 55536 CVSD chip. Digital speech data is clocked serially into the CVSD chip and converted into an analog signal. A preamp chip (MC1458) pre-amplifies this analog signal before it is sent to the mixer and final amplifier." From www.dreamstasys.com/system11.htm.

I would watch in bewilderment as my dad would play this very title on the same quarter for the entire time we were in the arcade. I would occasionally check in and pick his pocket for some more quarters and he was still going strong. Man I even remember the music jam. Brings back good memories.

Any Williams pinball, like Williams Arcade machines are just superb and well worth repairing and keeping.

Ron, you kept talking up that $30 solder sucker you use. I reluctantly gave in and tried it. OMG, best sder sucker ever!! Thanks!!

This is my favorite era of pinball. Things are sharp and fast. There are great features but not as ridiculous as some later stuff. I'd play that thing non-stop.

I love these videos (old but not REALLY old) System 11 and WPC95. Thanks for explaining the board. I came here after looking to get rid of the hum on my Defender but this was MUCH better time spent :-)

Love the sound card history! Excellent, thank you.

Love this channel dont know but the basics of electronics but i find it amazing of how these things work Reminds me of my days in the arcade when i used to watch (i stop playing just to watch) how the games got fixed so for me your videos take me back to those arcade years Thanks for uploading Greetings from Mexico

Agreed on the sound in this machine, awesome! Wish I could play it in situ. :D

Love the videos Joe! Thanks for bestowing your knowledge and methodical troubleshooting processes on us. What amazing sound this game has too. I love the games with those Yamaha chips. Reminds me of Swords of Fury and a lot of the games on Sega Genesis.

“Ridicule and mock us!”, never. You guys don’t deserve it for all of the value added service! Makes me want to plan a trip to Rock Hill!

One of my favorite pins great video thanks for sharing. Have a great week guys.

One of my favorite system 11 games voiced by mr pinball himself, always reflow the optics on the motor board, the station timing make you pull your hair out if they go cold

68B09. Funny you mention that it's important. I was doing some quick troubleshooting early on when I got Earthshaker and swapped out that 68B09 with a 6809. Made no difference in my background music not working. Fast forward a few days and actually started real troubleshooting only to discover that "B" is important. Cost me an hour or two of chasing my tail wondering why my clock line was stuck low at the 7474 before it.

Man, the owner is gonna enjoy this game so much when he realises how much of it he was missing out on before. Awesome game.

Great video! That relay is for the special "condition green" GI lights that happen when in multiball.

Thank you so much for the show and the extra effort you put in to making it for us. You are like having a friend in the business. Well, lets face it, you are a friend to all of us that watch. I look forward to watching your show each time because I know you will be funny, a little zany and kind enough to bring us along for the ride. Maybe we will learn something useful, maybe not, but you have a lot of heart and that's why we will keep watching. Have a wonderful Christmas and a happy New Year!

Ahhh the old familiar sound of 50Htz hum through a preamp shorted to ground. X I was really impressed when you found the terminator fragment that caused short in the molex plug that can only be explained by a time traveling cyborgs quantum displacement field!!

Good job Yamaha 2151! You rock it!

I just played this for the first time a few weeks ago. Pretty fun. Thanks for the video.

42:32 the right side light for the 75,000 bonus fixed itself!

Another detailed analysis and precision fix! Neat to watch.

The YM3012 is the digital to audio converter for the music. The YM2151 outputs floating point digital audio and requires an external DAC. YM3012 is stereo, but that was only used to that potential on Jokerz!

Nice this will help me fix my space station, has almost all the same problems

These videos are amazing, thank you. Keep ‘em coming!

Nice fix! That game needs a little TLC. Pretty fair condition.

Always loved the music on this one, has some kick ass bass :).

Fujitsu and Ramtron are the only companies who make F-RAM. It is fully compatible with SRAM, and in most cases only requires a simple adapter to function in place of it.

Love your videos my man! Keep up the great work👏👏👏

Well obviously it must be Christmas we're getting a video a day from Joe's classic arcade repair.. So now I do believe in Santa Claus or I mean RON CLAUS! As he flies in on a sleigh led by 8 microfarads. And one microfarad had a red incandescent bulb in its nose to help guide the way. Delivering repaired arcade games and pinball machines. To all the boys and girls paying customers. And whenever you hear a pinball machine make noise. An angel gets the high score!

Great video as always!

Ein sehr schöner Flipperautomat,....gefällt mir sehr!!!😊👍👍👍

The YM2151 and the accompanying YM3012 DAC generate the FM music and sound effects. I believe the MC1408 is the DAC for the digitized sound effects and speech. The big difference with the Mortal Kombat/NBA Jam sound board is the use of an OKI 6295 ADPCM chip for the digitized sound/speech. On the Crash sound board they are using the 6802 with an accompanying DAC as a wavetable synthesizer to generate the digital sound effects. This is similar to how the sounds on a lot of early Gottlieb solid-state hardware was generated.

Things I noticed: * Some flashers are not working (Side flashers) * Kickers not working * One segment of the score on player #4 is not working when in score mode (appears on scrolling effects but not scores). Bottom segment of one of the digits is missing (at time 3:18 of this video) I think it might be best to do a switch test and a full lamp test and full coil test on this.

When you were mentioning people that were mimicking you and mocking you, if one of them you thought was me I apologize but that certainly wasn't my intention 🙂

That machine is fug dup. Save it Ron!

The YM3012 is a DAC with serial input.

LM1458 is the most basic of dual op-amps. Several manufacturers still make them well over 25 years later. Can be had for about a $0.25 each in today's prices.

That sounds great.

The YM2151 chip is the OPM series synthesizer chip. 3.57 Mhz could be the NTSC color burst frequency. If the ROM ended in 64, that could be 64 kilobits, otherwise known as 8 kilobytes. For hi-fi reasons, I'd probably do redundant grounding. That is good practice. Like one person had an Apple computer with no sound. The design was poor in that they grounded through the shielding, and someone who fixed it before left the shielding off. So the one who got it used actual wiring to ground it and fix it.

I guess one crystal is for the sound chip and the other might be for the bus and the CPU. One is the NTSC color burst crystal and the other is 8 Mhz. On the relay, if nothing else, one could put a zig-zag bead of silicone glue on the wide sides of the relay. They will be the ones resonating with the clicking. The narrow sides likely aren't. The glue would muffle the clicking sounds.

What temp do you use on your soldering iron for board work. Your always looks neat compared to my hack jobs. Haha.

That humming sounds like either a bridge rectifier or capacitor has failed. It really is bad, so much that it sounds like power supply hum. Full wave rectified would give about 120Hz hum on 60Hz mains. Haven't ever heard it that bad on solid state before. I do hear that bad on tube amplifiers with bad caps. Sometimes the caps "reform" when they are turned on for a while and that can cause the hum to calm down. It sometimes tricks people into thinking the caps are okay. :). Anyway, I am just rambling before watching right through to the end of the video lol :) I know you have already fixed it.

Yeah I jumped to. That music was all of a sudden jump scared me.

Come on Ron, Come on Ron...Ron, come on now...everybody knows only Duracell batteries leak, energizers NEVER leak....Yes, I know people that believe that Duracell's are the only batteries that ever leak...yea...NOPE...LOL. Great game there, I remember that one from way back.

Looks like the 5T-5001 through 5T-5004 is an optional speech board for Black Knight.

The music kind of reminds me of Pinbot. That one came out after or before space station?

Space Station is cool game! 😎👍

The big square chip on the Mortal Kombat 2 board is a analog digital sound processor or a ADSP for short

That's whatcha call an awesome sound chip people 🕺 👋

Well damn if that music ain't rocking as good as ever....

30:45 Yes that chip is probably a ROM. The 6802 is the same as the 6800 but has 128 bytes of RAM built in so it doesn't need an external RAM chip. At least not for something simple like (I guess) generating sound from a ROM.

TNT amusements has a way to use a button battery to replace the double AA batteries. If you don't have a way to get the chip. Just a suggestion.

It says right on the display to ADJUST FAILURE. You just needed to turn the failure knob to off.

38:45 Are those two orange flashers supposed to be on? They look like they might be locked on. Looks like those boards need some TLC... or maybe it could be fuses for the solenoids.

Joe's Classic, Can electromechanical pinballs be converted to solid state OR is just not practical to convert them unless they're one of the late 1970s models that had E-M and solid state versions of the same cabinet?

Is this game a follow-up to Space Shuttle?

Cool vid as always

JOE CLASSIC, What fixed the HUM issue? The Special Solenoids don't use PIA chips or the Microcontroller to read the open/closed switch contacts which I get that part. The part I don't get is when the Special Solenoids contacts close what makes the contacts OPEN again since there is NO microcontroller or PIA chip sending a pulse to OPEN the contacts on the special solenoids?

that kind of 60 cycle hum can indicate a ground issue of some sort. i'm curious what you find.

You asked for us to point out issues we see... The one I notice that you didn't mention is that it's tilted slightly to the right. 😁

I have this machine too and my shuttle score lights in the middle stopped working. No power at the wire lead on that board. Any idea on how to fix it?

Nice machine 👍

Can the guy that produces the NVRAM boards get the chips from UTSOURCE assuming he has an associated account.

Often in audio gear when you have hum like that it's a bad filter cap on the PSU. I'm only halfway through the video...so I'm probably wrong. :)

Is there any acid leakage near the battery.

Oh, and could you use NiMh AA batteries and allow them to be charged?

Had to double check...he had the middle battery in backwards! Still better to do the mod external case. :)

Love me some Ron, people. Don't get electrokilled! And remember, "Knowing is half the battle. Go Joe!"

The sound in the 37th minute sounds very Commodore 64ish.

Replace filter caps in power supply and audio board.

Another fine video, thank you. The earliest Williams sound card used on World Cup and I believe on Contact and Disco Fever wired the volume control potentiometer backwards so you could not get good sound control. Williams fixed the problem with the sound card used in the Flash machine. Here is a video of how I fixed the problem: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-V9scjnDOB-E.html

why not already put a socket for a futur nv ram ? (battery replacement )

You can install Lithium batteries, they don't leak.

Ac filter cap

That sounds like a power supply ripple noise to me. main pwr supple cap. My guess.

i think the speech board was a Black Knight.

In the words of Joe..'Its broke!'😁

batteries are in backwards...

i see corrsion on battery pin

Fix it. You run barter town. you fix!

Yodelayheehoo

I’m only 3min into the video