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Burnt Connector

Mattyg48

Registered
Joined
Oct 24, 2021
Messages
31
Location
Uk
Alias
Matt
Hi all I'm seeking some advice please
I've noticed a section of lights in my backboard are not working after some inspection I've noticed what looks like a
Burnt connector ( see photo) can somebody advise if this is the problem with the lights and where I can buy some new connectors and what are they called? Thanks
 

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That there looks like a burned GI connector at J120 (I can't see the connector number on your photo). Backboard lights are GI (general illumination). Burned GI connectors are very common. Probably 50% of my machines came with burned connectors.

If I am right and that's the burned GI connector then you need to replace it and probably also the pins that it plugs into.

It looks to me like the connector has already been replaced as it is a different type (crimped pins) than the original IDC (like in the connector below). The fact that it has burned again suggests that the pins do need to be replaced or the new plug will also burn.

If you want to replace like original you need to get an eleven way connector like this:


with a keying plug

and if you are going to replace the header pins then this:


and you'll need one of these:


That's my opinion for what it's worth. Others may disagree!
 
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As above for all pinball parts ,if you need any help in deciding which part you need I always ask Andy by sending him a email etc he is also known as the legend 👍
 
Once you have the board out and pins replaced you could use this section on PinWiki to asset in checking for continuity in the GI circuit (Digital Multimeter required)

 
That's a common fail in Williams/Bally's of the WPC era. I've also known the weight of the cable (& the lower cables) pulling the connector so the connector is at more like an 85 degree angle instead of the 90.
A push back up into position and all the GI came back on. A swap to LED's will help stop these burning again.
 
I have found it much better to use Molex Trifurcon 0.156 phosphor bronze crimped connectors for this and make sure pins on the board are replaced. I have done this with every WPC I have owned and never had an issue. You may well have issues with the board as this overheating often fries the traces on the board too. If you don't have a de-solder station its best to gently pry off the white plastic from the male pins first, so that you can then de-solder and take out the male pins from the board one by one. Its easy to damage the board (or already have a damaged board from overheating so you may need to use a "stitch" to get the continuity back.
 
That replacement connector is also mis-wired. They are always wired like this

From left to right
White-Violet
White-Green
White-Yellow
White-Orange
White-Brown
Violet
Green
No connection
Yellow
Orange
Brown

The connector below is a parallel general illumination. The two plugs can be on either of these connectors.

So with the wrong wiring above, you may be driving two separate circuits from the same fuse ( which may cause it to blow ), and/or driving two circuits from one triac ( The thing on the heatsink that turns a circuit on )

The upshot is that most wpc machines use three circuits for the playfield on one connector and two for the backbox on the other ( there are exceptions ). So where theres a wire in the top one, the bottom one should be empty. SO once you've replaced the burnt connector, if you are not confident to replace the pins, you may find that you have good pins at the once burnt positions on the alternate connector.
 
@Mattyg48, that previous post is from Andy The Legend who owns Pinball Mania.
Great explanation and very helpful to keep these machine running.
Where are you in the UK Matty? There are a few people willing to help with these sorts of repairs.
 
Yeah I’ve saved this thread for future reference. Great info 👍
I’ve got the same burnt connectors on my sttng. Got the replacements from pinball heaven, just building my confidence up to try and replace them 😆
 
@Mattyg48, that previous post is from Andy The Legend who owns Pinball Mania.
Great explanation and very helpful to keep these machine running.
Where are you in the UK Matty? There are a few people willing to help with these sorts of repairs.
I'm in Birmingham.
@Mattyg48, that previous post is from Andy The Legend who owns Pinball Mania.
Great explanation and very helpful to keep these machine running.
Where are you in the UK Matty? There are a few people willing to help with these sorts of repairs.
 
Yeah I’ve saved this thread for future reference. Great info 👍
I’ve got the same burnt connectors on my sttng. Got the replacements from pinball heaven, just building my confidence up to try and replace them 😆
Mine did the same with general illumination, turned out to be a problem with the power driver board. Sent to pinball heaven and they fixed it.

Also had a problem with the fliptronics board, left flipper would stutter, again pinball heaven fixed it.

Both done super quickly and reasonably priced.
 
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Must be a common problem then. I may do as you did and send it off to be fixed rather than try myself.
My top right flipper works very intermittently and is very weak. Going to rebuild all the flippers and change the coils but may be that fliptronic board that you mentioned.
Sounds like they offer a good service, I’ll look into it. Cheers for the heads up 👍
 
Rewiring connectors is fairly easy with good tools and I always go Molex Trifurcon for the finished product. Whilst troubleshooting, I usually stick with the original IDC for speed.

The original power driver boards have had a long life but are usually able to be saved. Someone with the right troubleshooting skills can pinpoint the components that need replacing to reduce the amount of unnecessary impact.
@crsedgar linked to pin wiki with troubleshooting guides that are well worth looking at. Many of us find pleasure in the diagnostics and fixing.
 
Rewiring connectors is fairly easy with good tools and I always go Molex Trifurcon for the finished product. Whilst troubleshooting, I usually stick with the original IDC for speed.

The original power driver boards have had a long life but are usually able to be saved. Someone with the right troubleshooting skills can pinpoint the components that need replacing to reduce the amount of unnecessary impact.
@crsedgar linked to pin wiki with troubleshooting guides that are well worth looking at. Many of us find pleasure in the diagnostics and fixing.
As I move through each problem I do find it very satisfying especially as I’d never even seen beneath a play field before this year. I’ve always been more into arcade cabs, but the mechanical/physical side to pinball is starting to appeal to me more, however the difference in prices is less appealing 😆
 
Must be a common problem then. I may do as you did and send it off to be fixed rather than try myself.
My top right flipper works very intermittently and is very weak. Going to rebuild all the flippers and change the coils but may be that fliptronic board that you mentioned.
Sounds like they offer a good service, I’ll look into it. Cheers for the heads up 👍

I would start by rebuilding the flippers first. Some notes:

Make sure you get the right coil based on the manual rather than what's on the machine, operators had a habit of canablising coils from Adams they are slightly different. They will work as they did in mine but there not correct.

Take extra care to note the diode banding the grey bit around the end which indicates the current direction (I think). It's on the flipper coils. Be carefull with pictures and coil positions I didn't know about coils and put it back the same as the picture, however my new coils where different, the one on the machine where back to front. If you do it wrong you will damage the power driver board as I did 😂 which is what I sent it away for, it just happened to fix the light issue as well.

if after you change them and the flipper fires, but fires very quickly like a stutter after its the fliptronics Board and will be a capacitor or transistor (apologies I get them muddled up). If you haven't worked on boards before I would get a trusted person on here to fix. Either pinball mania as above in the thread or pinball heaven. Experienced forum members can advise better than myself.

The common problem with this is a drop in the 5 volts supply from the power driver board, it's very sensitive to slight voltage veriations. It can be the pins and connectors. your know you have an issue if the machine resets from time to time. One solution to prevent it is this


But change the connectors first

I would also change the canon wiring loom its an absolute pain to fix, but any slight damage to it causes all sorts of weird behaviour that's really difficult to troubleshoot. I only worked it out thanks to a forum member diagnosising. I can bet money when you take it off it will be taped they have a habit of wearing. Pinball heaven do a stronger cable. (The colours are slightly wrong on the molex to some thing can't remember which}
 
Excellent point on the coils, the existing ones are random strengths. I’ve got three new ones as per the manual.

Great heads up about changing the coils too, I would of definitely swapped the connections like for like so would of fallen foul of that!!

The flipper that is not working has got an open circuit on the stronger coil so hopefully that’s the problem.
I’ve read it’s worse if the coil shorts and so can blow something up further up the circuit.
Have you done the tie back mod on your sttng?
 
Excellent point on the coils, the existing ones are random strengths. I’ve got three new ones as per the manual.

Great heads up about changing the coils too, I would of definitely swapped the connections like for like so would of fallen foul of that!!

The flipper that is not working has got an open circuit on the stronger coil so hopefully that’s the problem.
I’ve read it’s worse if the coil shorts and so can blow something up further up the circuit.
Have you done the tie back mod on your sttng?
If there a mix of coils that will be a problem, it's possible that this might have damaged the fliptronics board, as I suspect is what happened in mine. However I'm not an expert only making an educated guess based on my machines behaviour.

No idea what a tie back mod is, so no 😁
 
Makes sense about the different size coils but hopefully not.
Just read about the tie back mod on various forums apparently it’s a solution to a design fault and can cause damage to the driver board.4191A2F9-8AC4-47CC-8EC0-8E027508835E.png
 
A word about diodes and 'tie-back', which are related;

Electronic pinball games require diodes on their coils, as an effective measure against an electrical effect known as 'back e.m.f'. When a coil carrying current and producing a magnetic field switches off, the collapsing magnetic field produces a spike of voltage as it does so. This could travel throughout the machines' wiring, causing unpredictable and damaging results. Luckily, the spike voltage is in opposition to the coils' proper supply (hence the term 'back'), so a diode across the coil terminals allows it to dissipate through the winding producing it. The manufacturers use the term tie-back for diodes used like this.

Since most diodes only conduct in one direction, their presence doesn't affect coils as regards 'proper' current; provided that the banded end of the diode is at the 'live' end of the winding, current can't enter the diode (think of the band on the diode as a barrier to direct current). Williams elected to make other arrangements for tie-back with the later System 11 and wpc system, placing the diodes for ordinary coils on the driver (or Aux Power for later System 11) board instead. This allowed mediocre technicians to change coils with less danger of damaging driver circuits from incorrect polarity. Flipper coils, being a special case, retained their diodes. Though games using Fliptronic II and later, i.e. Getaway onwards, have t/back diodes on the flipper board, and so should survive if a diode breaks off a flipper coil.
 
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A word about diodes and 'tie-back', which are related;

Electronic pinball games require diodes on their coils, as an effective measure against an electrical effect known as 'back e.m.f'. When a coil carrying current and producing a magnetic field switches off, the collapsing magnetic field produces a spike of voltage as it does so. This could travel throughout the machines' wiring, causing unpredictable and damaging results. Luckily, the spike voltage is in opposition to the coils' proper supply (hence the term 'back'), so a diode across the coil terminals allows it to dissipate through the winding producing it. The manufacturers use the term tie-back for diodes used like this.

Since most diodes only conduct in one direction, their presence doesn't affect coils as regards 'proper' current; provided that the banded end of the diode is at the 'live' end of the winding, current can't enter the diode (think of the band on the diode as a barrier to direct current). Williams elected to make other arrangements for tie-back with the wpc system, placing the diodes for ordinary coils on the driver board instead. This allowed mediocre technicians to change coils with less danger of damaging driver circuits from incorrect polarity. Flipper coils, being a special case, retained their diodes. Though games using Fliptronic II and later, i.e. Getaway onwards, have t/back diodes on the flipper board, and so should survive if a diode breaks off a flipper coil.
Interesting, thanks
 
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