Removing hacks from a WPC89 driver board


By pindergast

2 months ago


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  • Latest reply 2 months ago by snyper2099
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There are 55 posts in topic. You are on page 1 of 2.
#1 63 days ago

Why do people short the connection between BRs and capacitors on these drivers? Is it to avoid having to replace them? Continuity testing shows the trace is still intact between all these connections, so I'm confused why you'd want to jump it like this. I'm planning on removing these and replacing all the BR's and caps, is there any reason that would not be a working strategy here?

IMG_5F736F39D8B0-1 (resized).jpeg

#2 63 days ago

The traces from the bridges to the caps are on the top side of the board. When people replace the bridge/cap it tends to destroy the plated through holes if you are not careful or don't use the right tools. Running the jumpers bypasses the plated through holes and traces on the top side. I don't necessarily consider it a hack though. You'd have to either insert hole eyelets or stitch the holes to do away with those jumpers.

Sometimes people just do it for 'insurance'. If you find they're not necessary, remove them.

#3 63 days ago

DMM seems to show there's a connection without the jumpers in there; one that goes through the caps rather than bypasses them (seeing somewhere around 10-20 ohms, slowly creeping up as it should). Could've been for insurance I guess. Seems though like you'd be likely to run into issues if you are bypassing the caps though?

#4 63 days ago
Quoted from pindergast:

Seems though like you'd be likely to run into issues if you are bypassing the caps though?

They're not bypassing the caps. They're paralleling the traces on the other side of the board with jumper wires. If the plated through holes are compromised, the traces on the other side won't work and the filter cap is not connected in. I think that you think these are bypassing components, which they are not. They're just duplicating traces from the other side of the board.

#5 63 days ago
Quoted from pindergast:

Could've been for insurance I guess.

The connection might be intermittent, and someone was trying to fix a "reset" problem.
I'd advise swapping out ALL of the caps/bridges as it's really not necessary.
Some folks will reply with "caps have a service life of 10 years"...sure...but most times, hobbyists don't have the ability to remove the snap caps without damaging the through holes as is evidenced by the board you've pictured.

The only caps I change when a board comes in for bullet-proofing are C2 (12V circuit, leaks), C4 (5V circuit, contributor to resets), C5 (5V circuit, contributor to resets). If the bridges are working, I leave them. It's infrequent I see a board with a failed bridge.

I know others will disagree. But I'm in the "if it ain't broke, don't mess with it" camp.

Evidence: the two caps that are adjacent and horizontal from each other are 15,000uf caps connected in parallel, which yields 30,000uf capacitance. Those two caps filter the lamp matrix power, the same as the old 30,000uf cap in WMS System 3-7 games. How many times has anyone ever changed out that capacitor?

Regards
--
Chris Hibler - CARGPB #31
http://ChrisHiblerPinball.com/contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#6 63 days ago

Huh, the front of the board seems to be just fine and tests just fine. There's an eye missing on the top of one, but the rest of it is intact on the bottom (where the trace is). Not really sure why they'd go and jump these... going to just try to rebuild it and see if it works without the hax.

IMG_373E5F064FC5-1 (resized).jpg

#7 63 days ago
Quoted from ChrisHibler:

Evidence: the two caps that are adjacent and horizontal from each other are 15,000uf caps connected in parallel, which yields 30,000uf capacitance. Those two caps filter the lamp matrix power, the same as the old 30,000uf cap in WMS System 3-7 games. How many times has anyone ever changed out that capacitor?

Interesting you'd say that, when I bought the machine and parted it out for spares, about half the GI bulbs were burned black.

#8 63 days ago
Quoted from schudel5:

They're not bypassing the caps. They're paralleling the traces on the other side of the board with jumper wires. If the plated through holes are compromised, the traces on the other side won't work and the filter cap is not connected in. I think that you think these are bypassing components, which they are not. They're just duplicating traces from the other side of the board.

I see this now that the caps are off...

#9 63 days ago
Quoted from pindergast:

Interesting you'd say that, when I bought the machine and parted it out for spares, about half the GI bulbs were burned black.

Those bulbs don't go through the caps. GI is straight from the transformer, through fuses and triacs and then out to the lamps. The incandescent lamps tend to do that.

#10 63 days ago
Quoted from schudel5:

Those bulbs don't go through the caps. GI is straight from the transformer, through fuses (triacs) and out to the lamps. The incandescent lamps tend to do that.

Sorry, I mis-spoke. I was referring to the lamp matrix, not GI. I don't know why I said GI. This was a Doctor Who game and a majority of the playfield lamps for score multiplier, time extender, etc. were crispy.

#11 63 days ago
Quoted from pindergast:

Huh, the front of the board seems to be just fine and tests just fine. There's an eye missing on the top of one, but the rest of it is intact on the bottom (where the trace is). Not really sure why they'd go and jump these... going to just try to rebuild it and see if it works without the hax.

What happens at times when people remove the snap caps, it either pulls the eyelets off, or pulls the plating through the holes out. Then in that case the jumpers on the other side are necessary. If they test fine then you don't need the jumpers. Like I said they were probably there for insurance in case the holes were compromised.

#12 63 days ago

As someone who pulled off her fair share of eyelets when learning, why the heck is eyelet repair so expensive? A kit goes for like $250. That's crazy. It's just a little tube...

#13 63 days ago
Quoted from schudel5:

What happens at times when people remove the snap caps, it either pulls the eyelets off, or pulls the plating through the holes out.

Yep...and the through holes for C5 look to be pulled.
But if you can buzz from one side of the board to the other, you're good to go.
--
Chris Hibler - CARGPB #31
http://ChrisHiblerPinball.com/contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#14 63 days ago
Quoted from CadillacMusic:

As someone who pulled off her fair share of eyelets when learning, why the heck is eyelet repair so expensive? A kit goes for like $250. That's crazy. It's just a little tube...

I'm with you.
I looked into the components and tools to repair through holes. It just isn't worth it.
--
Chris Hibler - CARGPB #31
http://ChrisHiblerPinball.com/contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#15 63 days ago

So on that topic.. what's the "right" way to pull these snap cap legs without damaging the board? Since it's the physical force holding them in..

#16 63 days ago
Quoted from flynnibus:

So on that topic.. what's the "right" way to pull these snap cap legs without damaging the board? Since it's the physical force holding them in..

I don't know if this is the "right" way, but I use a desoldering iron with pump to clean out as much solder as possible, then I clip the ends of the cap as close to the board as possible. If necessary, I'll heat up each contact and give it a light wiggle to get the end loose. Eventually it pops out quite easily.

#17 63 days ago
Quoted from pindergast:

I don't know if this is the "right" way, but I use a desoldering iron with pump to clean out as much solder as possible, then I clip the ends of the cap as close to the board as possible. If necessary, I'll heat up each contact and give it a light wiggle to get the end loose. Eventually it pops out quite easily.

I would think having the clipped lead would be a surface more likely to drag and damage the through hole. Unless the snip is on the side before the widest part of the lead..

#18 63 days ago
Quoted from flynnibus:

So on that topic.. what's the "right" way to pull these snap cap legs without damaging the board? Since it's the physical force holding them in..

Here's what I do. I haven't torn a through hole since I started doing this.
1. Clip the leads of the existing cap close to the board.
2. Add solder to the leads, creating a small "dome" of solder
3. Heat both leads simultaneously with a broad iron tip. I have a "spade" type tip that can stretch across 9X .156 header pins at one time. It was pricey, but worth it since I perform this action so frequently on boards sent to me for repair. If you don't have a wide tip, use two irons. Heating the pads alternately and "rocking" the part is a poor substitute.
4. Once the solder on both pads is molten, see if light pressure can be used to "rock" the part out. If more than light pressure is required, then the through hole solder isn't completely melted.

Here's a video I posted using the tip to remove headers...nice.
» YouTube video

Rock on...
--
Chris Hibler - CARGPB #31
http://ChrisHiblerPinball.com/contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#19 63 days ago
Quoted from ChrisHibler:

have a "spade" type tip that can stretch across 9X .156 header pins at one time. It was pricey, but worth it since I perform this action so frequently on boards sent to me for repair.

@chrishibler Is that tip called a spade blade? Curious where to get one as several others have suggested that for dip switches and headers but I've never found one.

BTW I hope wire jumpers aren't now considered hacks or all my old battery damaged SS boards will have to be thrown out. I prefer to call them repairs or bullet proofing.

#20 63 days ago

That's a nice soldering tip, but geez, can it fit on a soldering iron that doesn't cost $400?

#21 63 days ago
Quoted from ChrisHibler:

Here's what I do. I haven't torn a through hole since I started doing this.
1. Clip the leads of the existing cap close to the board.
2. Add solder to the leads, creating a small "dome" of solder
3. Heat both leads simultaneously with a broad iron tip. I have a "spade" type tip that can stretch across 9X .156 header pins at one time. It was pricey, but worth it since I perform this action so frequently on boards sent to me for repair. If you don't have a wide tip, use two irons. Heating the pads alternately and "rocking" the part is a poor substitute.
4. Once the solder on both pads is molten, see if light pressure can be used to "rock" the part out. If more than light pressure is required, then the through hole solder isn't completely melted.
Here's a video I posted using the tip to remove headers...nice.
» YouTube video
Rock on...
--
Chris Hibler - CARGPB #31
http://ChrisHiblerPinball.com/contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

Is the only way you had that tip is through one of their full JBC stations? Doesn't look to be compatible with the pencils... and Wellers closest is only 10mm wide... and the Hakko spatula tips are only for their higher end series as well.

#22 63 days ago
Quoted from flynnibus:

Is the only way you had that tip is through one of their full JBC stations? Doesn't look to be compatible with the pencils... and Wellers closest is only 10mm wide... and the Hakko spatula tips are only for their higher end series as well.

I couldn't see it working with a pencil style as it would take a lot of heat to warm the hole attachment. Don't think a pencil style would have the power.

#23 63 days ago
Quoted from Mitch:

I couldn't see it working with a pencil style as it would take a lot of heat to warm the hole attachment. Don't think a pencil style would have the power.

I mentiin it inly in seeking cheaper alternatives than thei super expensive stations

#24 63 days ago

Man I just did a rebuild on my Dredd Driver board and still knowing about being careful with the c5 cap still broke the trace and had to install a jumper. I will try the 2 irons next time, going to do my Demo this weekend. Thanks for that tip

#25 63 days ago
Quoted from flynnibus:

Is the only way you had that tip is through one of their full JBC stations?

I'm not sure. I have two of those JBC irons. Picked them both up on eBay. They are really, really nice. The tips heat up on 7 seconds. No exaggeration.
That tip cost around $50 when normal tips cost about $17. But it's definitely worth it to me. It's a big time saver with as many boards as I do. Even WPC GI connectors can be easily split in half with a carpet knife and then the spade tip can be used.
--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#26 63 days ago
Quoted from KJL:

Is that tip called a spade blade?

I don't recall the "real" name for it...but that's what I call it.
I bought one that spans the 10mm used for WPC caps and found it incredibly useful.
After that, the wider one was a no brainer.
--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#27 63 days ago

Yeah it's called a blade... amazon.com link »

Edit: On British Amazon it's called a shovel

#28 63 days ago
Quoted from ChrisHibler:

Here's what I do. I haven't torn a through hole since I started doing this.
1. Clip the leads of the existing cap close to the board.
2. Add solder to the leads, creating a small "dome" of solder
3. Heat both leads simultaneously with a broad iron tip. I have a "spade" type tip that can stretch across 9X .156 header pins at one time. It was pricey, but worth it since I perform this action so frequently on boards sent to me for repair. If you don't have a wide tip, use two irons. Heating the pads alternately and "rocking" the part is a poor substitute.
4. Once the solder on both pads is molten, see if light pressure can be used to "rock" the part out. If more than light pressure is required, then the through hole solder isn't completely melted.
Here's a video I posted using the tip to remove headers...nice.
Rock on...
--
Chris Hibler - CARGPB #31
http://ChrisHiblerPinball.com/contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

Wow, that's a lot quicker than desoldering each pin individually. I wonder if weller has anything comparable to that tip.

#29 63 days ago

How does this compare to using the heat gun and pull method?

#30 63 days ago
Quoted from ForceFlow:

Wow, that's a lot quicker than desoldering each pin individually. I wonder if weller has anything comparable to that tip.

Nope - biggest is 10mm

#31 62 days ago

Hmm well installed new BR/Caps without the wires, and LED2 and LED4 aren'tt lighting, now to see if I can trace it back to the problem.

-1
#32 62 days ago

Looks like the issues are in the same places as they had put jumpers in. Growing really tired of these shit boards that are slowly becoming fire hazards. Another one for the trash heap.

#33 62 days ago

Huh? Why would you throw it out? There’s nothing shit about it. Repair it properly.

-2
#34 62 days ago

If it can't be repaired without hacking together a bunch of wires, any of which could go cold and ground out on the backplane at any time, the board has had it.

-1
#35 62 days ago

I might try an eyelet repair, if that doesn't work its trash. IMO it does a disservice to the community to try and salvage old broken boards. If there were more market demand for new equipment, we might see new blanks produced at some point, or better third party replacements than the crap we have today.

#36 62 days ago
Quoted from pindergast:

If it can't be repaired without hacking together a bunch of wires, any of which could go cold and ground out on the backplane at any time, the board has had it.

If you are going to throw it out, I'll take it off your hands.

#37 62 days ago

I've got C11 fixed up, will have to do some work on BR2 next, that seems to be the biggest problem

#38 62 days ago

It seems like the plated through holes have been pulled out. This is a VERY common issue and has already been mentioned in this thread. Plated through technology was new when these boards were made and no where near as good as today's technology, that's certain.

Repairing this issue with a couple of short jumper wires is NOT a "hack" - it is a perfectly legitimate repair. I'm talking as a technician in the electronics industry for over 40 years. NOT A HACK!

Repairing the through hole with an eyelet, or "stitching" with a thin piece of wire from top to bottom are both common and legitimate repair techniques as is using a short jumper wire.

Throwing this board away for the sake of doing a legitimate repair is plain silly. Any replacement will not be as good as the original. We manufacture numerous replacement boards (not this one yet) and I ALWAYS advocate repairing the original over replacing the board with ANY brand of replacement.

#39 62 days ago
Quoted from pindergast:

I might try an eyelet repair, if that doesn't work its trash. IMO it does a disservice to the community to try and salvage old broken boards. If there were more market demand for new equipment, we might see new blanks produced at some point, or better third party replacements than the crap we have today.

The entire repair community disagrees with you. Your board is 100% repairable, and there are countless folks who will take that “trash” off your hands.

-3
#40 62 days ago

I appreciate your experience, but it's a hack to me. A solder goes cold, a wire pops off, things slowly begin to ground out... really awful practice IMO and not the right way to do it. An ideal repair would be to replace the eyelet in the throughhole. I don't have the tools for that, but I did run a small wire through and solder it to the trace. Seems to test OK, we'll see how it does on the board. That's a hell of a lot safer than sticking wires across the back.

#41 62 days ago
Quoted from mschonbrun:

The entire repair community disagrees with you. Your board is 100% repairable, and there are countless folks who will take that “trash” off your hands.

Pinside doesn't constitute "the entire repair community", and I know at least a few Army certified technicians who find this practice awful. I appreciate there are differing opinions, but jumpers on junk boards have no place in the residential setting most of these machines are now in.

#42 62 days ago

Your. Board. Is. Not. Junk.

#43 62 days ago

So had to repair the through holes on most of the capacitors (from the previous work someone did when they turned this into "my first soldering project"), but all the voltages are up to par at the test points again and things are generally working... however the flippers are weak and the upper flippers drop and activate repeatedly if you hold them down. So guessing there's probably one more circuit that needs repaired.

#44 62 days ago
Quoted from pindergast:

Pinside doesn't constitute "the entire repair community", and I know at least a few Army certified technicians who find this practice awful. I appreciate there are differing opinions, but jumpers on junk boards have no place in the residential setting most of these machines are now in.

Jesus. We're soldering a pinball circuit board here, not wiring a nuclear warhead! I get that the wires are messy and ugly, but if they work, what's the issue? You can't be a total perfectionist or it will drive you mad.

I'd bet at least 50% of boards in existence have these jumper wires on them somewhere. That's a lot of "rubbish" boards!

#45 62 days ago
Quoted from arolden:

I'd bet at least 50% of boards in existence have these jumper wires on them somewhere. That's a lot of "rubbish" boards!

I bet most of those boards are good, and its just rubbish repair work.

#46 62 days ago

I have lost count of the number of circuit boards I have seen come from the factory with various jumper wires underneath to repair cock-ups, sometimes a few capacitors soldered directly to the track side and even additional transistors tacked on using double sided tape.

This is common FROM THE FACTORY!

I think you are being a bit precious about this legitimate fix without reason.

The machine is 25 +++ years old - come on.......

#47 62 days ago

Anyway, fixed up one more through hole and the driver board works as good as new now. No jumper wires. I think I might invest that $250 in a good through hole repair kit to do it properly. Through hole repair and trace replacement, IMO, is a much better solution than running wires that can fall off, ground out, or short the board if someone nudges wrong in the right conditions with a cold solder.

Not trying to insult anyone else's opinion on the matter... I know there are plenty of people who don't have a problem with jumpers- I've never particularly liked that as a solution. None of us would be having this conversation if someone would just do a run of driver board blanks that could be built out, like there are MPU boards and a few others.

#48 62 days ago
Quoted from pindergast:

A solder goes cold

solder doesn't 'go cold' - A cold solder joint is one that was done improperly when it was MADE - and fails later due to the physical movement.

Jumpers are not hacks - they are used even in production modifications. The point is they are done properly, with the lead being secured and insulated where necessary.

You're hung up on cosmetics which mean nothing. Please keep throwing your money away buying excess boards... that usually means more spare boards for the rest of us.

-3
#49 62 days ago

So much drama on this thread. Geez. Why does this community have to be so goddam elitist that they can't respect others' opinions.

#50 62 days ago
Quoted from pindergast:

Through hole repair and trace replacement, IMO, is a much better solution than running wires that can fall off, ground out, or short the board if someone nudges wrong in the right conditions with a cold solder

all of these concerns are matters of 'poor implementation' and have nothing to do with the use of jumpers

Wires that can 'fall off' are wires that were not secured with tape or glue
Wires that can 'ground out' are wires that were not insulated and trimmed properly
Cold Solder joints are bad solder joints - don't make bad solder joints

Quoted from pindergast:

that they can't respect others' opinions

Because it's based in ignorance.

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