(Topic ID: 354892)

Centaur II weak launch

By Powerorbs

3 months ago


Topic Heartbeat

Topic Stats

  • 78 posts
  • 12 Pinsiders participating
  • Latest reply 40 days ago by Quench
  • Topic is favorited by 3 Pinsiders

You

Linked Games

Topic Gallery

View topic image gallery

IMG_2791 (resized).JPG
IMG_2790 (resized).JPG
IMG_2789 (resized).JPG
IMG_2788 (resized).JPG
IMG_2787 (resized).JPG
KBPC3510W.jpg
IMG_0231 (resized).jpeg
Centaur_Rectifier_Board.jpg
IMG_0231 (resized).jpeg
IMG_0230 (resized).jpeg
IMG_0228 (resized).jpeg
IMG_0229 (resized).jpeg
IMG_0227 (resized).jpeg
RectifierBoard-54_Plugs.png
IMG_6347 (resized).jpeg
IMG_6348 (resized).jpeg
There are 78 posts in this topic. You are on page 1 of 2.
#1 3 months ago

Hi, thanks for having me.
I have managed to keep my centaur 2 working well in the 20 years I have had it despite lack of electronic knowledge, just using the practical skills I have and the excellent information provided by the online community.
My only problem at the moment is that the multi-ball kick to playfield is too weak to get the ball up the ramp and lift the spring steel flap.
The mech seems free to move and the solenoid fires just with insufficient power.
I have reflowed the solder on the solenoid expander board but that made no difference. The relay clicks but a bit sparky - I don’t know if that’s an issue.
Can anybody walk me through diagnosing and sorting out this problem?
Thanks

#2 3 months ago

Sorry, this was my first post. Apologies if I have not conformed to forum conventions I’m unaware of.

#3 3 months ago

Welcome to Pinside. Head to the Centaur owners club and have a look. You may find help there.

https://pinside.com/pinball/forum/topic/centaur-clubmembers-only

Quoted from Powerorbs:

Sorry, this was my first post. Apologies if I have not conformed to forum conventions I’m unaware of.

#4 3 months ago

Thanks. I went through all of those and although ball launch was discussed I didn’t really find out what to do about my situation

#5 3 months ago

Bally pinballs this age are having connector problems, and when the electronic connections aren't making good electrical connection, they will 'steal' power from parts that need power.

If your rectifier board is original, it is overwhelmingly likely that you need to replace all the pins that the connectors plug into.

Then replace the connectors with crimp-and-stuff (not IDC) connectors. On the ends of the wires use trifurcon terminals.

If this hasn't been done in the past decade, it likely needs it, and there is a kit available:

https://www.marcospecialties.com/pinball-parts/CKBLY

The next thing is the Solenoid Driver board if it is an original bally board.

The pinwiki has some recommended fixes:

https://pinwiki.com/wiki/index.php/Bally/Stern#Solenoid_Driver_Upgrades

But what I'd be concerned with is replacing connectors, pins and plugs.

I think I'd rebuild the rectifier board first, see if that got more reliable 'snap' to the coils, but after that it's the Solenoid driver board.

Let us know if this helps!

#6 3 months ago

Thanks for your reply. I bought the game back in 2005 off eBay from a dealer in Germany who shipped it all the way to my door in the UK. It had been ‘repaired’ by them and presumably during its hard life so that it played 100%. But it sure ain’t pretty under the playfield! Very few new replacement parts and some pretty bad looking solders. I suspect that there are a variety of non-standard bodges going on under there too. But apart from fuses, some reflowed pins, replacement drop targets and a a couple of board components I have had to do very little to keep it working well. (The say-it-again board has now failed of course so it plays without the reverb.) I suspect the time might have come where I need to do some substantial refreshing like you suggest.
The rectifier board is the one with the fuses, right?

#7 3 months ago
Quoted from Powerorbs:

Thanks for your reply. I bought the game back in 2005 off eBay from a dealer in Germany who shipped it all the way to my door in the UK. It had been ‘repaired’ by them and presumably during its hard life so that it played 100%. But it sure ain’t pretty under the playfield! Very few new replacement parts and some pretty bad looking solders. I suspect that there are a variety of non-standard bodges going on under there too. But apart from fuses, some reflowed pins, replacement drop targets and a a couple of board components I have had to do very little to keep it working well. (The say-it-again board has now failed of course so it plays without the reverb.) I suspect the time might have come where I need to do some substantial refreshing like you suggest.
The rectifier board is the one with the fuses, right?

Yes the rectifier board has the fuses

#8 3 months ago

Not sure the kit in the link is correct for my board or not - see photo.

IMG_0188 (resized).jpegIMG_0188 (resized).jpeg

I unclipped all the connectors and reconnected them and the game still plays fine apart from ball launch which is now noticeably worse. So I think the issue could be down on this board as you suggest.

#9 3 months ago

D'oh!

Yeah, surprisingly, there doesn't seem to be a rebuild kit for this board.

The last one of the games that used this board that I repaired I ended up buying a replacement board.

#10 3 months ago

Thanks.
Any point in me taking the board out and reflowing joints behind connectors or is it usually the blocks themselves that are problematic?

#11 3 months ago
Quoted from Powerorbs:

Any point in me taking the board out and reflowing joints behind connectors or is it usually the blocks themselves that are problematic?

If the rectifier board was the problem, all solenoids would be weak and you would particularly notice it with the flippers. Suffice to say I think your problem is elsewhere.

In your shoes I would first open the coin door and try and watch the ball launch and travel up the rails to see if there is some kind of mechanical issue with the balls movement being erratic.

Did you by chance replace the incandescent lamp next to the solenoid expander board with a LED? If yes, put the incandescent lamp back.

It could also be that the solenoid expander board relay contacts are getting burnt - you mentioned they were sparking.

Did you do any work on the game directly prior to this issue happening?

#12 3 months ago

@powerorbs, It's often a very good idea to heed the wisdom of @quench. The guy seemingly knows these early ss Ballys in and out, and has been a Godsend (maybe literally?) for me, and many others on this site. He's not unlike St. Jude, the patron saint of lost causes! LOL

You can learn much from him.

#13 3 months ago
Quoted from Quench:

Did you by chance replace the incandescent lamp next to the solenoid expander board with a LED? If yes, put the incandescent lamp back.
It could also be that the solenoid expander board relay contacts are getting burnt - you mentioned they were sparking.
Did you do any work on the game directly prior to this issue happening?

Here’s the thing- I cannot see any lamp associated with the expander board. I wonder if the previous owner has replaced it with some other component. The game used to work 100% with no bulb (unless I’m just not seeing it). The relay is pretty sparky, more than think might be normal. The only thing that happened prior to this fault is the machine sitting unused for a few months.

IMG_0189 (resized).jpegIMG_0189 (resized).jpeg
#14 3 months ago
Quoted from Quench:

If the rectifier board was the problem, all solenoids would be weak and you would particularly notice it with the flippers. Suffice to say I think your problem is elsewhere.

Appreciate the experience speaking here. Thanks Quench!

#15 3 months ago

pic wasn't relative

#16 3 months ago

No lights (without playfield insert) near solenoid expander.
There is one down by the other little ‘aux driver’.

IMG_0191 (resized).jpegIMG_0191 (resized).jpegIMG_0193 (resized).jpegIMG_0193 (resized).jpeg
#17 3 months ago

Whatever is going on with solenoid expander missing bulb or otherwise the machine used to launch multiball fine for years until recently. I even had it on ‘attract’ mode during parties where it launches all 5 balls every 15 minutes and invites you to destroy Centaur!

I’m pretty sure there’s no mechanical obstruction issue with the rails/flap. The lunch mech feels free and it works ok if you flick it manually. The solenoid is firing but seems underpowered.

I wonder if the simplest but not necessarily cheapest diagnostic would be to swap out the solenoid expander board (I suspect the relay).

#18 3 months ago

You might also check that all the screws in the lower rail mechanism are tight and that nothing has vibrated loose. The lower launch mechanism is a fairly complicated bit of kit and there's a lot of opportunities for things to move and get out of adjustment. On mine, I had very inconsistent multi-ball launches so I wound up putting a slightly stronger coil to better shoot the ball up the ramp.

#19 3 months ago
Quoted from Powerorbs:

No lights (without playfield insert) near solenoid expander.

Sorry, I just rechecked the schematics and the solenoid expander is driven by the solenoid driver board, not the typical method Bally uses with the lamp driver board. Disconnect and reconnect J5 at the solenoid driver board in case there's some connector issue.

Quoted from GSones:

You might also check that all the screws in the lower rail mechanism are tight and that nothing has vibrated loose. The lower launch mechanism is a fairly complicated bit of kit and there's a lot of opportunities for things to move and get out of adjustment.

See here ^^^
A friend had a similar issue with the screws getting loose on the assembly holding the trapped balls that caused problems with ball positioning at the kicker back coil.

Note: if you do go down the route of changing the solenoid expander board, it will have a jumper that you must configure for Centaur, otherwise the board will cause solenoid fuses to blow because of the unique way the solenoid expander board is wired on Centaur.

#20 3 months ago
Quoted from Quench:

Sorry, I just rechecked the schematics and the solenoid expander is driven by the solenoid driver board, not the typical method Bally uses with the lamp driver board. Disconnect and reconnect J5 at the solenoid driver board in case there's some connector issue.

Thanks for that detail. I’ll make some more checks.

#21 3 months ago

Reseating J5 on driver board hasn’t effected anything. I thought for a moment that the microswitch part way up the chute was hanging things up but was mistaken. I can’t see any mechanical problems with the chute, all fasteners tight and top flap free to move.
I’ll take a look at the mech that loads the balls in the chute, pretty sure all is well there too though.

#22 3 months ago

It is tough to see, but make sure the ball loads into the chute and sits against the catapult. If the catapult hits the ball mid-stroke it causes the weak launches because the ball rattles around during its journey up the chute.

I had to setup a camera in the cabinet and play a few games to catch a bad launch in action, and the ball not sitting against the catapult arm was the cause.

#23 3 months ago

Good call! I’ve had that happen with the outhole kicker, when that little rubber bumper that the kicker arm rests against had worn way down, causing the armature to sit too far from the ball.

Quoted from Xenon75:

It is tough to see, but make sure the ball loads into the chute and sits against the catapult. If the catapult hits the ball mid-stroke it causes the weak launches because the ball rattles around during its journey up the chute.
I had to setup a camera in the cabinet and play a few games to catch a bad launch in action, and the ball not sitting against the catapult arm was the cause.

#24 3 months ago

I can’t see mechanical issues with the chute or ball positioning. It seems like the kicker force is low. Could a sparking relay reduce the power getting sent to the solenoid?

#25 3 months ago
Quoted from Powerorbs:

Could a sparking relay reduce the power getting sent to the solenoid?

It could.
I don't have my Centaur near me to check (maybe someone else here can) but by the schematics I don't think the relay should be sparking that much due to the moment it gets activated at the low part of the rippling DC phase.

You can pop the relay plastic cover off and give the relay contacts a bit of a clean with some sand paper.

But before doing so there's some other things to check:

The solenoid expander board is switched on via the lamp driver board and feature lamp power. Please measure the feature lamp voltage at the solenoid expander board. Thick blue wire at pin 1 - the black cover over the wires on the connector slides off to expose the wire terminal connections. The blue wire should measure over 6VDC.

The solenoid expander board requires ground and 43V for full power of the kickback coil. If we assume 43V connection to the playfield is good since it powers all other coils and you didn't mention they are power affected, then that leaves the ground connection. It comes from the rectifier board at J1 pin 9 (black-white wire). This goes to the solenoid expander board at either pin 3 or pin 4 (schematics don't specify). You could try to temporarily jumper a wire from the GND test point on the rectifier board to the solenoid expander at pin 3 to ensure good ground connection as a test.

#26 3 months ago

Had the same problem. Switched from the 25-950 to the 23-900 and it worked perfectly.

IMG_6347 (resized).jpegIMG_6347 (resized).jpegIMG_6348 (resized).jpegIMG_6348 (resized).jpeg
#27 3 months ago

Thanks for all the help so far.
I struggled to work out how the relay cover can be removed but just got brutal with it.
I took some abrasive paper to the contacts but that hasn’t reduced the sparking or increased the solenoid power.

#28 3 months ago

Get or make yourself a jumper wire with an alligator clip on the end. Clip the jumper wire onto the coil tab with the wire with the orange/black tracer. Close the playfield and feed the other end of the jumper out through the coin door. Set up the game and then touch one of the side rails with the jumper. Hold it for a one-Mississippi count.
If the ball launches out as it’s supposed to then you have an electrical issue. If it launches out sluggishly then you have a mechanical / coil problem.

#29 89 days ago
Quoted from 29REO:

If the ball launches out as it’s supposed to then you have an electrical issue. If it launches out sluggishly then you have a mechanical / coil problem.

Great. Thanks. Will try it.

#30 89 days ago

I’ve uploaded a video to Vimeo (link below) showing me conducting the test.
I fire up the machine and drop the ORBS targets in order to trigger a multiball launch in the normal way.
You can see the ball can’t quite make it past the steel ramp and up into the playfield. The game tries again another 3 times.
Then I try the jumper wire a couple of times, touching it to the side rail. On the second attempt the ball only just makes it out.
It should kick the ball out with more power than this, it used to.
It looks like maybe I get a tiny bit more power with the jumper but not really enough.

https://vimeo.com/937950440

#31 88 days ago

Good job! Nice video! You have something wrong with the launch mechanism itself. Look for a loose pin on the launch arm and check for bent brackets. Look at the coil stop and make sure the bolts aren’t stripped out. Take it off and inspect the stop, they can break loose. If all of that is in good condition then swap to a 23-900 coil with a new sleeve and stop. FYI: That is a flipper plate repurposed for use in the launch mech.

#32 88 days ago

have you removed the solenoid expander board from under the playfield and checked the header pins for any dry solder joins?

have you looked at the connector to make sure any pins inside broken and just sitting there?

a reflow of the header pins wouldn't hurt.

what voltage do you have at the coil?

definitely sounds weak in the video.

#33 88 days ago

I did reflow the pins on the solenoid expander board. The mechanism appears to be fine to me but obviously I have no comparison. Coil stop is solid. I tried measuring voltage at coil in test mode but I couldn’t get a good reading when it fires, not a good sign I guess.

#34 88 days ago

If you have a digital volt meter you won’t be able to measure the pulse voltage - you would be able to see it using an old mechanical volt meter. You would see the needle spike to the voltage present. You can check the voltage by measuring between the brown wire on the coil and the side rail. I expect that you will see around 43 vdc. No need to start a game, that voltage is always present. When you remove the coil stop and unless the stop inside is broken, you should upgrade to a stronger coil as mentioned earlier.
For testing purposes, you could put a flipper coil on there and use both the primary and the secondary and I’ll bet you would see a serious launch. You don’t need that kind of power but that will tell the tale.

#35 88 days ago
Quoted from Powerorbs:

I’ve uploaded a video to Vimeo (link below) showing me conducting the test.

There is more value in performing a video recording as Xenon75 mentioned with the camera in the machine looking at the launch mechanism.

Quoted from Xenon75:

I had to setup a camera in the cabinet and play a few games to catch a bad launch in action

#36 88 days ago

Agree with Quench. You must eliminate any possible mechanical issue.

#37 88 days ago
Quoted from Quench:

There is more value in performing a video recording as Xenon75 mentioned with the camera in the machine looking at the launch mechanism.

Fully understanding the dynamics of the ball trough/launch mechanisms on Centaur has been one of the biggest challenges for me owning this machine. Lord knows I’ve had a few of my own. It’s so awesome to follow these threads and see how others deal with their own issues that arise. Though I can’t input much here regarding the issue experienced by @powerorbs, I really learn a LOT from those who can. That camera idea is spot on!

#38 88 days ago

I had this happen on my CII after a playfield swap. Turned out that one of the supporting brackets for the launcher rail wasn't aligned just right and caused one of the wireform "rods" to kink in just enough to rob power from the ball as it was getting launched.

May not be your problem but from what everyone else has said that eliminates power/coil issues, it could be something like this.

It wouldn't hurt to take apart the coil from the mech and clean and resleeve the coil to eliminate any buildup causing problems.

#39 88 days ago

Powerorbs Quench begs the question, How can you be sure that the ball is sitting squarely in the trough and is sitting up against the launch arm? You have to make sure this is right. On the positive side is that the problem is occurring every time so that should make it a bit easier to spot the problem.

#40 87 days ago
Quoted from 29REO:

Powerorbs Quench begs the question, How can you be sure that the ball is sitting squarely in the trough and is sitting up against the launch arm? You have to make sure this is right. On the positive side is that the problem is occurring every time so that should make it a bit easier to spot the problem.

https://vimeo.com/938612124

#41 87 days ago

From your video looks like there's some slop in the mech. Hopefully that bushing on it is just a flipper bushing so it will be easier to find. The coil looks like it's moving a bit in the mech when firing, you need to put a wave washer or 2 in there to take up that slack. If the plunger or coil stop is very worn need to be replaced. Coil sleeve replaced.

Full rebuild, and anything that's worn and seems loose needs to be replaced.

#42 87 days ago

Here’s the launch mech failing:
https://vimeo.com/938612124

And the other end of the ramp:
https://vimeo.com/938618009

#43 87 days ago
Quoted from slochar:

Full rebuild, and anything that's worn and seems loose needs to be replaced.

Thanks.
A bit more difficult to source parts in the UK than US.
I’m sure I can get a coil and probably stops and sleeve. Is the plunger a standard part or specific to this mech?

#44 87 days ago
Quoted from 29REO:

If all of that is in good condition then swap to a 23-900 coil with a new sleeve and stop

Locally I can get hold of:
AQ-25-500/34-4500 or
A-24-570/34-3600
And I think I have spare flipper stops.

Either of these coils worth trying?
Are the interior diameters standard?

Edit:
Those are old Bally coils like in my Centaur. I can also get hold of Williams:
23-800 or
AE-24-900

Which of those would you recommend?

#45 87 days ago
Quoted from Powerorbs:

Here’s the launch mech failing:

Your video shows what you've been saying all along that the coil activation looks slow/weak.
For some reason the download link on your videos comes back with "no links were found" meaning I can't download and play them locally in slow motion for more insight.

Coils don't wear. It was working. The problem is not the coil itself.
First simple thing to try is cleaning the coil sleeve in case it's got metal dust robbing magnetism from the plunger rod. I usually metal polish the plunger rods so they glide more easily.

But ultimately this looks like an electrical issue. I don't see any feedback to my suggestions in post #25.

Quoted from Powerorbs:

Then I try the jumper wire a couple of times, touching it to the side rail.

The ground connections to the side rails are usually rusted so they aren't the best place to borrow ground for a high current test. I would retry that test but use the GND test point on the rectifier board since it's right at the source of solenoid ground.

#46 87 days ago

Wow. The unit looks pretty good and the ball does sit in there properly - I don’t see any obvious damage or wear, although that’s hard to see in a video. The pulse length looks good but the “pull” appears slow. I have to observe mine to compare. I’m curious, dod you measure the voltage between the brown wire on the coil and ground (One of the side rails)? Something else has me curious, take a jumper wire and clip one end to the brown wire tab on the launch coil and the other end to the brown wire on one of the other coils that works properly. Retest the game.

#47 87 days ago
Quoted from Powerorbs:

Locally I can get hold of:
AQ-25-500/34-4500 or
A-24-570/34-3600
And I think I have spare flipper stops.
Either of these coils worth trying?
Are the interior diameters standard?
Edit:
Those are old Bally coils like in my Centaur. I can also get hold of Williams:
23-800 or
AE-24-900
Which of those would you recommend?

You could also take off a few hundred turns of wire off the existing coil. I've never done this myself but I have EM friends that do this for pop bumper coils to get some extra kick on them instead of Hi-Tapping the transformer so don't quote me on the exact number of turns to remove (maybe someone else who has done this can chime in).

#48 87 days ago
Quoted from 29REO:

Something else has me curious, take a jumper wire and clip one end to the brown wire tab on the launch coil and the other end to the brown wire on one of the other coils that works properly. Retest the game.

Did this. Same issue.

I’m now wondering that maybe all the solenoids COULD all be down on power.
The game will still play OK ish with slightly weak target resets, slings and even flippers, it’s only going to be most noticeable on the launch which has a minimum power requirement to get the ball up on the playfield.

What is the best/simplest check that I’m getting the correct voltage to all the coils please?

(I realise I probably haven’t completed all the suggested tests so far, I’ll try to get to them.)

#49 87 days ago
Quoted from Quench:

You could try to temporarily jumper a wire from the GND test point on the rectifier board to the solenoid expander at pin 3 to ensure good ground connection as a test.

I tested GND continuity between test point on rectifier board and pin 3 on expander board = 2 ohms resistance, presumably it should be 0. Is that useful information?

#50 87 days ago

you should have about 43VDC at the coil.

measure with the red probe on either solder tab on that suspect coil and ground. look for some braid for ground.

try measuring on the bottom panel on the rectifier board J1 pin7 to ground. The metal panel should be fine as a ground reference.

your mech appears to be working smoothly but like you reckon, loss of power.

now wondering if your transformer is jumpered correctly to suit your mains yet you say you have had this pin for a while and it was fine.

did see the video showing it repeatedly trying to launch the ball.
'looks' to be okay, how does the mech feel operating it by hand?

check your fuse holders that they are holding the fuses nice and tight. You shouldn't be able to rotate the fuse. F4 a 5A is for the 43VDC.

Promoted items from Pinside Marketplace and Pinside Shops!
$ 69.00
Gameroom - Decorations
Pinball Pimp
 
$ 17.50
Lighting - Led
Pinballrom
 
$ 18.95
Eproms
Pinballrom
 
5,999 (OBO)
Machine - For Sale
West Chicago, IL
From: £ 135.00
Electronics
Retro Electro Designs
 
From: £ 135.00
Electronics
Retro Electro Designs
 
$ 8.00
Electronics
Third Coast Pinball
 
From: $ 649.95
Lighting - Led
Pin Stadium Pinball Mods
 
$ 10.00
Playfield - Decals
Metal-Mods
 
$ 10.00
Playfield - Decals
Metal-Mods
 
$ 33.95
Eproms
Pinballrom
 
Trade
Machine - For Trade
Incline Village, NV
$ 33.95
Eproms
Pinballrom
 
$ 18.95
Eproms
Pinballrom
 
4,000
Machine - For Sale
Mesa, AZ
$ 69.00
Gameroom - Decorations
Pinball Pimp
 
From: £ 110.00
$ 10.00
Hey modders!
Your shop name here
There are 78 posts in this topic. You are on page 1 of 2.

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 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.