(Topic ID: 35328)

Vid's Guide to Bulletproofing Williams System 3-7

By vid1900

11 years ago


Topic Heartbeat

Topic Stats

  • 1,137 posts
  • 216 Pinsiders participating
  • Latest reply 17 hours ago by Inkochnito
  • Topic is favorited by 652 Pinsiders

You

Linked Games

Topic Gallery

View topic image gallery

Screenshot_20231113-133240 (resized).png
Screenshot_20231113-133225 (resized).png
PXL_20230716_200651820 (resized).jpg
PXL_20230716_200647261 (resized).jpg
PXL_20230716_200601305 (resized).jpg
PXL_20230716_200556910 (resized).jpg
PXL_20230716_200522876 (resized).jpg
PXL_20230716_200508141 (resized).jpg
3 bay (resized).jpg
board2 (resized).jpg
supply (resized).jpg
3A4FC091-431F-43F6-A84A-4CFAE8734C64 (resized).jpeg
EB6D6648-4D78-451B-BACA-51E3B1AF41D9 (resized).jpeg
green led (resized).jpg
cage (resized).jpg
put back (resized).jpg

You're currently viewing posts by Pinsider la_porta.
Click here to go back to viewing the entire thread.

#397 7 years ago

Vid,

Thank you for all of your help. I am just learning, but tonight I undertook the simplest and most important mod of the rectifier diode boxes. Somewhat tough with the way the wires are in my box, but works like a charm.

image_(resized).jpegimage_(resized).jpeg

#399 7 years ago

Vid,

I wanted to know what sorts of boards I have in my pin. Since you seem to know everything about this stuff, can you tell me what vintage of boards I have, be it System 3-6 or whatever might be? I got a bunch of good pictures for you, decent lighting and all. Also...I'm not sure if the diode/resistor replacement mod for high-voltage displays was done...can you chime in on this? I really appreciate it.

IMG_3370_(resized).jpgIMG_3370_(resized).jpg

IMG_3371_(resized).jpgIMG_3371_(resized).jpg

IMG_3373_(resized).jpgIMG_3373_(resized).jpg

IMG_3372_(resized).jpgIMG_3372_(resized).jpg

#402 7 years ago

Much appreciated, ill be sure to check it out. Wish I could get the damn focus to work better!

7 months later
#502 7 years ago

Question for you Vid: the guy that runs the local electronics store tells me that 12,000 mfd capacitors are no longer available. I saw that in your example you swapped a 12,000 for a 15,000...will that still be ok for the 12,000 on a Williams System 6 sound board? Mine looks like it's about to burst out one end and it has to go! Do you think the sound quality will be affected?

#504 7 years ago

Fair enough, I believe you! However, would a 15k work just as well or cause issues?

#506 7 years ago

Thanks a bunch...I'll also remember to make sure that I don't buy into his BS next time.

1 week later
#507 7 years ago
Quoted from vid1900:

After the caps, to finish bulletproofing the high voltage section we need to swap out some diodes and resistors. Remember, you only need to do this if you are using high voltage score displays.
First we swap the 100v 1N4764 Diodes with 91v 1N4763 (Z2 and Z4). This dims the displays slightly, but makes them last 10x longer, a very fair trade off figuring how expensive displays are nowadays. Note that the Diodes have polarity. The banded end goes towards the top of the board.
Next, Williams recommended that the 680 ohm resistors (R2 and R5) get changed out to 1.2K ohm 1/2 watt resistors.
Finally, R1 and R4 are usually stressed. Replace these with 39k ohm 1 watt flameproof resistors. Solder them slightly above the board surface for better airflow.

Vid, it appears that the kit from Great Plains contains all the upgrades that you suggested for the high-voltage section. Can you confirm? I'd like to purchase the kit, as it is far easier than hunting down everything individually.

https://www.greatplainselectronics.com/Downloads/W3-11_HV_Kit.pdf

#510 7 years ago

Just started replacing the caps on my Firepower soundboard. Also checked the fuses, and someone installed 6 amp ones when they should be 4 amp. Just like Vid has said before, don't assume anything about who has done what previously!

#511 7 years ago

So I replaced all the caps on my sound board. It appears to work just fine. I had a question though: Capacitor C12's orientation on the Firepower.com soundboard schematic from Phil Butcher lists the polarity as being from negative at top to positive at bottom. My board, however, has the positive side plus symbol printed on the top mounting hole. I mounted the capacitor as per what the board listed, not the schematic. The cap that was there was quite small and old, and I could not decipher which end of it was which. Does anyone (or Vid) know why this discrepancy exists? Is it an error in the schematic or the board itself? Which is correct?
Recapped board (minus zip tie!)Recapped board (minus zip tie!)

#513 7 years ago

I'll have to get a good quality, up close shot tonight.

#515 7 years ago
Quoted from barakandl:

The first versions of the sound board have the polarity marked wrong on the PCB for that cap.
You can tell if you have the first version because there is a 1uF bypass cap tacked down across the 5v rail on the top left area of the sound board. The later version (with the correct polarity mark) has through holes for this cap.

Looks like mine is one of those (check my photo above, I just replaced that one...and wondered why the heck there were no holes!). In that case, I assume I should then remove the cap C12 and orient it according to the schematic, not based on what is on the board. What does that cap do, anyhow? The board currently works with it backward!

#517 7 years ago
Quoted from BJM-Maxx:

The cap still does its job when installed backwards but will have a much shortened life.

Well it is getting swapped around regardless. I was under the impression that electrolytic would only work in one direction...I must have been misinformed. Thank you for the help.

#519 7 years ago
Quoted from barakandl:

replace it with a new one. It may be damaged. 1uF is cheap enuogh cap not to gamble on.
in many circuits, a backwards polarity cap will heat up and explode.

It's brand new, turned on for about 10 minutes once...still no good in your opinion?

#521 7 years ago

That's a very good point. I'll pick one up on the way home. Thank you for the help!

2 weeks later
#522 7 years ago

Vid, for the two diodes D7 and D8 that you suggest to replace, I don't have 6A4s on hand, but I do have some 3 amp, 400PIV diodes in my spares box. Are these worth it to upgrade, or is the amperage not enough to be a good replacement? It appears that the MR500s were 3 amp, but I would assume you chose 6 amp ones on purpose. Would it not make any sense?

#524 7 years ago

So I finished upgrading my high-voltage supply area with the Great Plains kit (minus replacing the transistors), and it works great: displays are dimmer slightly, as advertised, but it's not a big deal for keeping them alive for much longer. However, I now notice a "twitch" or flicker in the first digit of my 4th player display, as well as a not-as-often flicker in the second digit of the same display. All the others are in perfect order. My question is: does this flicker represent a problem with the display that I didn't notice before simply because it was brighter? Is it possibly a flaky connection somewhere, or does it represent the beginning of the end for that display?

#526 7 years ago
Quoted from vid1900:

Try plugging and unplugging the display a few times (with power off) to clean the contacts.

Turned out to be loose wire to terminal contacts on the 4th player harness. All fixed! I'll also get some before and after pics of the display brightness. As you said, it is minimal. I hope to keep my originals and not upgrade to LED, so this is a much welcome upgrade. Thank you for all of your work and help on these forums.

#527 7 years ago

Installed some 6A4s last night...those suckers are huge!

1 year later
#630 5 years ago
Quoted from zacaj:

I had a Laser Ball that locked on when I first powered it up. I didn't know about the issues like this at the time, so I left it on while checking voltages, a bit later I heard a 'plunk!' as two of the resistors fell out of the board and landed on the bottom of the head

That's one way to desolder, I suppose.

4 months later
#713 5 years ago

NVRAM is awesome. If you can desolder/solder a chip, you can do it easily. Vid had instructions on how to do that in this thread. Here is what you want:

https://nvram.weebly.com

Best change I made, never have to fool with batteries again.

1 week later
#717 5 years ago

I also had a funky problem once where I was stuck in diagnostic mode because the screw in I believe the upper right hand corner of the battery holder was not present. Amazingly, this screw serves as a connection point between the front and back of the board. Withit it, the circuit was not complete and kept the machine in diagnostic mode.

Promoted items from the Pinside Marketplace
$ 9.95
Eproms
Pinballrom
Eproms
$ 69.00
Gameroom - Decorations
Pinball Pimp
Decorations

You're currently viewing posts by Pinsider la_porta.
Click here to go back to viewing the entire thread.

Reply

Wanna join the discussion? Please sign in to reply to this topic.

Hey there! Welcome to Pinside!

Donate to Pinside

Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!


This page was printed from https://pinside.com/pinball/forum/topic/vids-guide-to-bulletproofing-williams-system-6?tu=la_porta and we tried optimising it for printing. Some page elements may have been deliberately hidden.

Scan the QR code on the left to jump to the URL this document was printed from.