25¢ per foot seems expensive for 18 AWG stranded wire in PVC. With the bulk discount, that's about double what industrial suppliers are charging. On the plus side, you can get 10 colors in any length so there would be very little waste. Buyer beware, and shop around.

Pinball suppliers are great for pinball parts, but this generic stuff can easily be obtained elsewhere. Is this your store? I only ask because the website does not say much about them, and the limited inventory focused on pinball makes me wonder if it's one of those temporary niche stores. The company name is generic but the inventory is pinball focused. Not necessarily a problem, but when something new pops up, one should be careful.

I wonder if anyone still makes wire with the 3 colored stripes like in an old Gottlieb? Or maybe not; by color code, not counting 000 and 999, that would be 998 unique stripe combinations.

But I asked the question in reply to this user...

That's the same one I got for my Gottlieb. It worked fine.

I agree with both of these statements. Very very unlikely every winding in the transformer is blown. And besides, the voltage for some of your lights is still coming from someplace.

Are you sure you had your meter set to read "AC", not DC volts? Depending on the meter and absent any offset voltage, when reading AC using the DC setting, it shows zero.

As long as the schematic is correct, that would explain zero volts.

You may want to go back and fix post 35:

And you also have 1 jumped to 3, and 5 jumped to 7, right?

Power it down and test the resistance of the windings at lugs 8 to 10. If you're getting zero volts, I would expect open windings (infinite resistance) here... and that of course would be confirmation of a failure.

What is your resistance reading from 8 to 10 ?

I don't believe continuity is broken, because I think he previously stated that he read 1 ohm between 8 & 10. Then again, I am not entirely sure he took that reading with the transformer isolated from the corresponding circuit.

Yes. According to your schematic, if you pull out fuse F2, then transformer winding at lugs 8-10 will be isolated from the machine for a proper reading.

Double check the integrity of your DMM meter leads... sounds like a lead may have an internal broken connection or where it plugs in could be flaky. Not uncommon. Your DMM also relies on an internal battery for resistance readings. Make sure it's good.

Whenever I get flaky readings, I check to make sure my leads are fully seated into the DMM; sometimes they pop out halfway.

It's doubtful that you would be able to fix a break in the wire by running solder down in. Transformer windings are enamel coated so solder cannot stick to that. You would have to expose the break, scrape off the enamel coating to shiny bare copper, and even then soldering wire ends butted together is a very weak connection.

Please post a photo of where you believe the break is at.

What is sticking out of the paper behind it? Is that a piece of debris or is this a wire that is supposed to be connected to this lug?

Somebody who is more familiar with how this particular transformer is wired up should chime in here.
Pinside_forum_7459754_0 (resized).png

Then if that's true, it's the connection from the lug to the winding. Scrape the enamel from this wire here and you should be able to verify this via measurements. In other words, instead of touching lug 10 with your DMM, which is now a lug not connected to anything, touch it to that piece of wire behind.

You should be able to repair this now as long as you don't break it off farther inside. Copper is subject to work hardening, so the more you bend it, the more likely it will break off.

IMO, I would get an UN-insulated wire butt splice (as pictured) and solder it onto the end of this piece of wire. Then you can use another piece of wire to make a fresh connection back to lug 10.

61YGB2WMCyL (resized).jpg

If you haven't sanded or scraped away the enamel, it's going to be difficult to get a solid reading on the broken end of a small wire.

I would clear off about 1/4" to 1/2" or so if possible. Then use some flux and solder to tin the wire. Then once the wire is tinned, it should be easier to get solder to wick up into a butt splice. Try to find a butt that is just barely large enough for the wire to slip in; the closer the fit, the better the solder will wick.

Excellent!

FYI - Most ordinary paper takes an incredible amount of heat before it combusts. Something close to 500° F. Kraft paper? Manilla envelope paper?

However, to avoid disintegration over time, maybe something like parchment paper (baking aisle) would work? Otherwise, can you just re-attach the original paper? Something like varnish or enamel should work well as an adhesive.

EDIT: Plain brown paper bags are made from kraft paper.

Varistors are for clamping spikes and are wired in like capacitors (across the voltage). In other words, a blown varistor would not stop anything from powering up. Measure your incoming voltage starting with the cord, and be methodical.

A flaky power switch would not be an uncommon failure.

Yes, a switch is either open or closed. Sounds like you might need a new switch. Also, you could use resistance mode.... should read close to 0 ohms when the switch is closed (on) and infinity when the switch is open (off).

Not electrically "parallel" as that is something else entirely. Two poles that operate together... DPST (double pole, single throw).

main-qimg-4649e058c2fc1e129a52a6b7afa40095 (resized).png

Yes. Sounds like it.

Remember, when measuring voltage at the switch, you will measure zero volts on a hot line if you measure across a closed switch. Measure voltage across both lines (hot to neutral) instead, on one side and then on the other.

main-qimg-4649e058c2fc1e129a52a6b7afa40095 copy (resized).png

When measuring resistance, you would measure through each side of the switch instead.

main-qimg-4649e058c2fc1e129a52a6b7afa40095 copy 2 (resized).png

I don't know. My meter doesn't do that.

But if -1 is the same as infinity, then your meter would always read -1 while you're holding the probes in mid air.

Sure, why not. You will have to plug/unplug to turn it on/off. Otherwise, if you have an ordinary house switch, you could just temporarily wire that up on the hot side and leave the neutral side connected without a switch. That's how most appliances are wired up... only the hot wire is switched. Just make absolutely sure you are switching the hot wire on/off... verify it on your cord/plug. On a standard 15-amp, 110 VAC plug in the US, the narrow blade is hot (also sometimes brass color), and the wider blade is neutral (sometimes silver color).

Easier yet... do it your way... hard wire... and just plug the machine into a switched power strip or surge strip.

I'd still verify the hot/neutral wiring on the power cord regardless.

What wire? Look at your schematic.

Or are you talking about hot vs. neutral?

According to your schematic, what circuit is Fuse 1 protecting, and does it verify as 10-amp?

Suspect a major problem, short, in Bridge Rectifier 1 if the 10-amp fuse immediately pops. Surely, this is the root of all of this....

Well, there you go.

You'll need the schematic of the rectifier board. Then start at the J1 header working your way through testing each of the components. At 10 amps, surely something is shorted to ground.

I cannot be more specific because I do not have one here, nor do I have the schematic.

Time to call an electrician. Seriously. This is a very unsafe condition.

You are supposed to read zero volts from neutral to ground. You should never see voltage between neutral and ground on a properly wired outlet.

However, if you cannot read 110/120 VAC from hot to ground, you have a serious problem.

Verify your meter... do you read 110/120 VAC from hot to neutral?

Those are the expected readings.

Looks good.

Yeah... I have to agree. And I'm honestly having a hard time following along. One minute, all voltages test good and the next minute, some are zero. This machine definitely has something loose or broken, probably hidden inside of heat shrink or tape.

What's your test method here?

A fuse can have continuity but the fuse holder or clip could be garbage.

Not just your soldering. Verify every connection in the circuit. You may have something under shrink wrap or tape that is not even soldered at all. The amount of time spent on verifying voltages is concerning.

I had originally suggested that you fill the uninsulated crimp with solder. That method should never come loose.

Sounds reasonable.

In a previous post, you reported 183 VAC at transformer tabs 8 & 10 so that's good.

However, in various other posts, you've reported many different voltages at TP2, one time as low as 33 VDC. (Loose connections?)

Looking at the schematic, with 183 VAC input, if you're now not getting something that is at least 230 VDC at TP2, then you only have to test/inspect diodes CR1, CR2, CR3, CR4, resistor R3, and all the wires/connections in between. (Assuming F2 is solid.)

Screen Shot 2023-03-30 at 2.58.38 PM (resized).png

I would not worry so much about +/- 10 VAC variation right now.

If you should have 230 VDC when the transformer is putting out 173 VAC, then a little more (183 VAC) should give you a little more than 230 VDC... not less.

Get a toothbrush and some alcohol and scrub off all that excess flux. Otherwise, visually, I don't see any issues. You really need to test those 4 diodes in the bridge circuit. Scroll down to the diodes section for test procedure. This is a test with power off.

https://www.testmultimeter.com/2021/11/multimeter-test-bridge-rectifier-diode.html

"working" or all diodes passed the DMM test?

I suggested the DMM test for all diodes, because if one diode is bad, you're still going to read DC output but it's going to be partial.

I don't know what else to say. The circuit is super simple and if you're getting full AC voltage from the transformer, then you should see full DC voltage at the test point.

Pinside_forum_7504182_0 (resized).png

Where exactly are you putting the other DMM lead when testing DC voltage at TP2 ?

I am not a Stern guy, but I would think that the test points would have a specific test procedure associated with them. What does the manual say to do regarding taking these readings?

Just looking at the circuit, without capacitors, you're not getting smooth DC at TP2...

output-wave-forms-of-full-wave-rectifier-1 (resized).jpg

Top shows the 60 Hz AC sine wave coming out of your transformer.

Bottom shows the pulsating "DC" coming out of your "full-wave bridge" rectifier, oscillating between zero and full voltage 120 times per second.

Short answer: What you're reading depends on the quality of your DMM...

https://electronics.stackexchange.com/a/572935

(for kicks, you could try reading TP2 using the AC scale)

Yep!

Actually a good meter might read RMS, and a cheap meter might read the average. But basically the idea is that you are not going to read the pulsating DC the same as you're reading the AC, which is RMS.

TP2, IMHO, is not a great test point given the pulsating DC that must be measured. At this point, I'd verify the four diodes and resistor, and their connections (you did all this already), and just move on.

Like others stated more recently, we've beaten this horse to death.

Following along with this thread at times can be frustrating. Like there is something obvious being missed.

I think I had asked about this several pages ago. Something seems off.

Whenever I see that, I immediately assume my meter, leads, or technique and try again. Usually it's my meter, leads, or technique. In those situations, I get out the alligators and clip on my leads after verifying the setup with a known voltage. Once the meter is clipped on, then it's easier for me to poke around looking for flaking connections.

Well, I have no idea (w/o seeing schematics) if using your ground braid is the same as reading across here...

Pinside_forum_7504182_0 (resized).png

Very simplistically, yes.

So there's a 10-volt drop between the negative side of the bridge rectifier and your ground braid. I am not saying this is causing any of your issues, but I would suspect a dirty or inadequate ground connection someplace....

Look at your schematic. How/where does the negative point of the bridge rectifier between CR3 and CR4 connect to the braid? Start here and physically trace it back through each connector and connection point.

As snyper2099 already pointed out, maybe this was the source of all these whacky voltage disappearances.

Did you clean the metal mating surfaces before tightening this connection?

If you had to add a screw, then what exactly was holding it all together when you found it? Can you post a photo?

I don't understand why we are jumping backwards. I thought the ground issue was already found and fixed here...

It would not hurt anything to hook it up. Maybe your 10-volt differential will go away.

He said it was TP2 on the rectifier board. Isn't that coming straight from the transformer and rectifier?

Pinside_forum_7504541_0 (resized).png