I would recommend to try replacing the ribbon cables from the MPU to sound board and MPU to display system first. A vast majority of these types of problems are caused by flaky cables, believe it or not. Then if it is not the problem, at least you'll have a known good reliable cable in the system and the original as a spare.

There is nothing "special" about them, just make sure the computer cable you sub is standard pin arrangement and nothing weird like a crossover. Make sure the pin 1 is indicated by stripe or mark it yourself before installing.

This is almost never good.

Shouldn't be a peroblem, the original is Motorola, and looks like the HD prefix number is a Hitachi replacement. However, if it is getting smoking hot that's probably not a good sign. Marco Specialties has the Motorola part if you'd like to try it:
http://www.marcospecialties.com/pinball-parts/6809E

Might be a typo. Could try contacting them directly. These are www.pinballpcb.com boards, and on the wwwpinballpcb.com website are listed as $75 with a pull down box to specify which ROMs you want. I've never ordered from them, but you could also try ordering it direct from them and you might even save a couple bucks.
http://www.pinballpcb.com/Sys11BackgroundSound.htm

That is a diode, not a resistor, and it does belong there. You may have disturbed that grubby wiring on this coil, or perhaps the other power feed and the other flippers. All that wiring is poor and needs to be redone correctly. The diodes should be checked, and those EOS switches need at least a cleaning, if not complete replacement by the looks of it. You need to have healthy powerful flippers.

http://techniek.flipperwinkel.nl/wms11/index2.htm#flip0
https://pinside.com/pinball/forum/topic/vids-guide-to-upgradingrebuilding-flippers

Hey bud. Congrats on the GL! I'm a new owner also and have been playing it and fixing it in combo. It is very addictive!
So similar to yours except yours has nicer playfield I think.

When I got mine home I noticed right away I had no displays and no bongo drums too. I bought it on the street corner as "working". .. I have all background target sound effects though which I'm happy about.

So after realizing I had a stitched together pin bot powersupply board and it was beyond what I wanted to spend time on I bought a new xpin power supply board - just like I did with my other game SS. It is a great product and I'm a firm believer in having a rock solid powesupply on these older timer machines...

I did check the pinbot board high voltage side and got 93v +\- so it seemed all good. But I ordered the replacement board anyways. Sooooo I put new board in and presto all displays work perfectly!! Still no bongos though...so only 1/2 way there.

Just thought I' d let you know my partial success. Your thread is perfect timing, so I will be following closely. Going to check my U5 chip temp. I have combed all old threads on no background music on GL and high speed because they had the same music board and more HS made...lots of info but nothing definitive. Wish I had a reversed cable, but no..tried that! oh well. Hope we get it sorted out and you get your flippers fixed.

It is a two-stage flipper button right? Light pressure activates lower flippers only. So I bet you have a) grubby wiring to clean as mentioned and also b) all flipper button switch blade contacts that needs a good de grubbing and light flex stone. Bet that does the trick.

Well, this is why there are games that are clean and usually come with a warranty for service, and then there are used games that are in need of much attention. Most people can learn some basic pinball repair, the thing that is most needed is some patience and some education. If you just want to quickly fix and play a game, that's not likely going to happen. Most of the time even us who have the electronics training will find a used game needs a lot of things fixed to work properly and reliably...and even if you have the training, you need to know how the game system you have operates, and not all are the same.

The most important things you can do right now if you want to fix these games yourself is
A) READ. Read the repair docs. Read pinball tech articles. Read everything related to pinball repair.
B) Learn to solder. Practice to solder. Correctly.
C) Learn how to use a DMM

OK, that said, let's take one problem at a time. You still have a game with some flipper problems, correct? --- where's it stand now? Exactly the same? Describe to us what is happening with each flipper at this point in time since you did all that mechanical work.

Have you tried adjusting the gap so that it just opens at the end of stroke. Probably 90% of the time on EOS-based flipper systems, weak flipper is caused by either EOS contacts dirty or opening just a little too soon.

Usually excessive sparking is an indication of heavy pitting, oxidation, corrosion. Properly filing clean can sometime resolve, but if a contact is not able to be cleaned and filed correctly so that the contacts mate completely, it may be time to replace it.

Absolutely. Your EOS contacts need to be clean and touching each other firmly to transfer the current, which translates to *POWER*, to your flipper coils. Usually,removing these switches so they can be bent properly is the way to improve the pressure of the contacts.

Did you measure the coil resistance? Maybe it is clapped out? Just a thought.

Glad you found it. BTW, the switch down by the button would be call a "flipper cabinet switch", not EOS. EOS (End-Of-Stroke) is used to switch the coils to hold voltage at the maximum flipper extension, and is found on the flipper mechanism. Just for future reference.

Right on! That is a great find...nice straightforward fix. I'll be very interested to see how your new sound board goes when it arrives.

I'm looking at the first photo you linked in post 1 and I cannot be sure but your power supply caps look original. The two parallel black ones as I understand it they do get old and need replacement., I think your display problems might be related to the power supply as mentioned above.

Also, my sound board looks exact like yours ...meaning the big cap in the middle of the board looks burnt or at least stained from heat coming from the bank of ceramic resistors below on the CPU board. I'm guessing decades of heat exposure like this affects the chips and cap on the sound board. I may try to replace this cap and see if any solution here. More troubleshooting this weekend.

Well, it's health should be examined with a DMM (or oscilloscope). Basically, you want a tight tolerance of the 5VDC with very low AC ripple. Filter caps can dry out. Typically, if they haven't been replaced in 10 years, they are cheap enough to just replace. Good stable power means you are much less likely to be playing along and then *surprise!* something weird happens, like the game suddenly reboots.
Nobody wants that in the middle of shooting their best game.

Look into one of the digital type systems eg. Pinscore, Rottendog, Xpin Lots of benefits as to longevity and low power consumption.

Cereamics? Possibly you mean cement power resistors. They get hot because- well, that's what they are supposed to do: dissipate power as heat.

Ceramic, cement, yes those ones. I know they are supposed to get hot. But what is the heat effect on other components right above them over years of use? As you can tell I'm not an expert and just learning the terminology. Good thing you're along with us WO to keep us on track thanks!

I was certainly eyeing those replacement display kits too, but in this case fluked out with my new power supply board. Ymmv of course.

Pinballs were lucky to be designed for little maintenance within approximately a <10 year life span. When you are talking about >30 years...that can have it's share of problems.
As long as certain things are running, they can often run well beyond the rated lifespan. Typically, electrolytic capacitors start to dry out. Mechanical parts wear out from friction. Most everything else that is working will likely continue to keep working.

There's a huge difference between preventive maintenance of common failure parts, and excessive replacement of those parts that could run years, if not decades. There's little reason to replace a part that is working, and will probably outlive your own lifespan. That's pretty much wasteful, IMO.

Just for the record in case it comes across like I'm trying to start an argument here...I'm not. I'm also not saying to replace the cement power resistors for maintenance, that would be silly. ...carry on.

Hi,
Man, that sucks your new board did not solve the problem! What a downer, but, it is at least a slow process of elimination. I'm not very useful to your questions, sorry.
Have you read this thread? It is the most thorough thread on this specific game/board I have found in my research....unfortunately for us, it was just a reversed cable! A lot of useful troubleshooting info though:

https://pinside.com/pinball/forum/topic/williams-system-11-missing-background-music-investigation#post-2295117

I'm along on this journey also with the same problem, so I hope together we can solve this! Weekend coming up means good troubleshooting times.

Among other error messages I get on start up that I'm dealing with, I get adjust switch 23 - 4 bank. Are you sure yours is switch 4 bank four? Maybe we start with the easy stuff eh? I forget, do you have a copy of the manual for this game?

There isn't a "music chip". Background audio involves a whole lot of components...it's more of a "process". Think about it - the entire BOARD you replaced was involved in processing music. Now that you have replaced it, you can be reasonably assured that it is not the problem. Did you replace the ribbon cable and make certain it is installed correctly? This is so common it is almost cliche, replacing a board because of a cable problem. Once that is done, if it is still bad, you'll need a occilloscope or logic probe to start poking around the MPU.

Just as follow-up on this thread, I took a chance a few days after you ordered a sound board. I ordered one direct from pinballpcb, and finally installed it yesterday .....and....
The bongo drums pump out the beats! It was a blind attempt for a fix, and, in this case it worked. I hope your resident board expert can help you Luzur, it seems you may have some problem on the cpu board that you and I both don't yet understand.

Btw. As soon as way out mentioned a logic probe above, I was thinking to myself ...hmmm another piece of hardware to buy and get familiar with. It seems a whole new language to me on some of the troubleshooting threads I have read, and grateful that others like WO have the skills and willingness to help us newbies. Trust it will all work out for you, just keep at it...it is worth it! I love playing GL, very fun game.

Hi, it was plug and play.

Thinking about it a bit more about your error question on start up, since your lower displays are out you won't be getting the 2nd half of the error message. So mine with all working displays says error four bank 4 on the top 2 displays and 23 below, so that is switch 23 on the 4 bank drop targets up top...according to the manual so without working displays it is a bit awkward to find out which target is not working. The 23 is listed on the lower display...bottom right but your display is not working.

I have the error message mentioned, and I have yet to dig into it but I'm confident it will be something straightforward like a dirty contact or broken wire...you may want to hunt around for the obvious.

So we are at a cross roads right with your machine. You and I don't know how to take on a cpu board and such with IC soldering, logic testing, etc so that leaves 2 options. 1. Send it out to pros 2. Replace small aux boards as troubleshooting points to obvious "suspect" areas.. Or combo of both ..so that would be 3 options..

Obviously all options can be expensive and I'm not saying to buy a new cpu board just because!!!

I still think you would be best to start with your power supply board. Either get it tested / rebuilt or replace with something like an xpin board. Without steady, proper voltages coming into the cpu, any problems are likely compounded.
Do you get a flicker at all of the lower displays?

I look at it this way...
You have a super playfield on that machine, and it is a great game. So why not invest in it.
If you can afford to fix it, you should. Just a lesson in patience... keep at it man! You'll get it sorted out.

Did you check for positive 5 volts and negative -12 volts at the background sound board?

The voltage comes from the power supply, if they are bad that is why neither board works.