Was this the lead still attached to the chip or the circuit board?

You read this on pin 5?

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The chip is oriented upside down from that picture according to the pin 1 dot. I get the 2.1 read on the leg which is still in the circuit board. Pin 5 was reading 0 I believe.

If U-49 pin 5 is Low (0.8 volts and below) then pin 6 should read the same. Check this upper part of the cut lead to know if the chip is good. The lower part of the cut lead is connected to the circuit board and U-45 and SR-20. If you read 2.1 volts when it should be 5 volts, then cut the lead #2 on U-45. Then retest the voltage.

Ok, I’ll get over there this afternoon and let you know. I’ll take pictures to confirm I am cutting the right leads.

Thank you again!!

All chip pins are counted the same way. Find the notch and count counter clockwise around the chip.

cp (resized).png

Ok, I get 3.1VDC on lead 5, 0VDC on lead 6 and 2.1 on the leg stuck into the board.

I cut lead 2 on U45 and nothing changed over on U49.

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Here is one of the 6 special solenoids circuits. The 7407 is U-49, the 7402 is U-45. The red stars are the cut pins you have made. So when you test the circuit board trace, it should read at 5 volts if SR-20 is good.

ss (resized).PNG

What is SR-20? Is that another IC? Assuming you checked my work there, it looks like that must be bad correct? Also, is there a way to test the 5 volt line just to make sure something really stupid isn’t happening?

It is a number of resistors contained in a SIP package. The one pictured is a bussed resistor pack where one side of each resistor is connected to a common pin marked with a dot most of the time.

pasted_image (resized).png

Find SR-20 and test pin 1 the common pin. It should read 5 volts.

SR-20 is 5V on pin 1. Wtf does that mean?

But what does the other pins read?

In order of the pins.

5
.1
.1
3.6
2.1
2.1
2.1
2.1
2.1
2.1

I should also ask, where are you seeing that schematic @grumpy? I don't see anything in the manual that illustrates that circuit.

The top of page 28 in the manual.

All of these are bad but pin 1. Either SR-20 is bad or something crazy is going on here.

Any way to work backwards and test what's going to the SR-20? I'm super close to pulling the trigger on a rottendog board, even though it will crush my potential profits on this machine :/.

With the power off measure the resistance from pin one to pin two. Then measure the resistance from pin one to pin three, and so on. What do you get.

Will do...and if I want to order some new ones...https://www.marcospecialties.com/pinball-parts/5019-09362-00?

Are there better ones? You always seem to know which ones are better .

Pin 1 to all over pins. Is this this broken?

4.1
2.5
4.5
4.5
4.6
3.8
4.5
2.6
4.5
4.5

Yes they can crack causing all sorts of stuff. There is no better version of this.

You need this.

https://www.greatplainselectronics.com/proddetail.asp?prod=4610X-101-471

Didn’t fix it. The resistor was good after I pulled it out of the circuit. I put the other chips and the new resistor back in, no change.

You got something strange going on there. You may have to send it to me.

There is a repair guy in town with a test setup. I’m going to go over there and have him take a look. If that doesn’t work I will gladly send it over.

Keep everyone informed.

It is not the board. Everything tested correctly.

Ok, got it back in and for some reason everything is working…except my analog sound is making a loud buzzing noise. :/

Very strange.

This is the ghost in the machine syndrome... when it happens to me, I try and remember EVERYTHING that I did when I removed/disturbed the harnesses and pulled out the board, especially any screws or metal to metal contact points, routing of audio cables and power lines and making sure they don’t cross over each other or are back to their factory location (after years of maintenance, though, you have to rely on us old farts with Pinbots that were taken out of mainstream play 25 years ago for some pics of original cable routing). I then turn on sound test and start wiggling and pressing any mounting point, wire bundle, or other suspected culprit. If it gets worst or better, or crackles or sputters, you now have some location that you know may need insulated, moved or further checked. But one note, Pinbot creates sound from both the CPU and the sound board. So check the audio cables that come from the CPU board. IJ15 and IJ16 in the top left of the CPU board. Good luck.

Oh and check the shield braid on analog audio cable is still soldered to the shield pins on the connectors. They have a tendency to break loose with mechanical disturbance and pulling them off the connector jacks.

Ramp entrance and exit switches. Neither of mine work, I've removed the ramp and do not get continuity no matter what I do. I've cleaned with a piece of paper still no continuity.

Any reason I can't replace these with a micro switch?

Nope. Have fun. But have you checked the ramp harness is plugged in under the play field first? I went down this path once. After replacing the ramp, I thought I had plugged it back in. Would have bet money on it. Would have lost it, too. But that was my senior moment, certainly at this point you would check the plug and connectors and all pins are making good contact? Doesn’t kill you to look. Reflow the solder on the leaf switches? Micro cracks look like the Grand Canyon to electrons.

Yup plugged in soldered, tested continuity. The leaves look like a gorilla tried to adjust them with a pair of vice grips. I"m going to try and reshape them, I got one working kind of last night but the contacts are all jacked up and not making a quality connection, i can get a switch registering with a ball maybe 3 of 7 tries.

Yeah, Been there on a set flipper switches in my South Park... ultimately had to replace them.

I bought a restored all-LED Pinbot a few months ago. It works, but there is an audible 50 Hz hum (I am located in Europe, therefore 230V/50Hz power) coming through the speakers. The volume of the hum always stays the same no matter how the volume knob is set. Lights have no effect to the sound of the hum - it's always pure 50 Hz.

In order to get rid of it I replaced all 8 caps on the power supply board (see shiny new blue caps on the picture) but unfortunately there is no improvement.

What else could I try?

IMG_0077 (resized).JPG

Got an O-scope? Thats what I would do next, go sniffing my audio circuits looking for where the signal is getting injected. If it is coming out of the DAC, then look at the power coming into those areas of the circuit. Also, look for the shielded audio cables shield pin to wire braide connection, those are notorious for breaking due to the heavy solder joint.

Mine had a loud hum when I got it. Circuit board didn’t have all of the screws holding it on. Once I bought more screws and got it properly grounded it was completely gone. So maybe go through and check that you have all of the screws and they’re all tightened down?

Finally finished my pinbot.

- full led conversion including flashers, trough light, backbox light, flipper button lights and Star post lights...comet pinball, take my money!
- playfield strip, clean, wax, new rubbers and pinballs
- replaced the vortex ramp, orbit ramp (thanks @freeplay40) and visor (thanks @freeplay40)
- all new plastics set
- new vinyl decals for visor and ramp
- rebuilt center target mechanism with new limit switches and motor
- replaced numerous sockets and switches
- bent and installed new eye socket wire forms
- cliffys installed for center drop target and saucers
- new plastic shields for saucers
- rebuilt shooter and flippers, upgraded to fliptronic style springs
- new pinscore displays and ribbon cables
- miscellaneous electrical gremlins exorcised
- replaced / upgraded backbox and cabinet speakers
- installed tournament roms (Matt’s basement arcade ftw)
- removed the 30 year old mummified frog from the bottom of the cabinet

...and most importantly, got the GC score and knocked my buddy Shane off the leaderboard.

Happy flipping!!

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Unfortunately I haven't got an O-scope. Where is the audio cables shield pin? Would you please mark it on a picture? Thank you.

When reinstalling the visor is there a trick to get it to sit down properly When I hooked mine up and power up it doesn’t rest in the down position.

I once was talking to Steve Richie about the new ramp in my High Speed. I said I was having a little issue with my shooter rod alignment. He commented, "Do you know how we dealt with that at production?"..."A 2 by 4 and a hammer!"

Probably not the cure you are looking for. I would loosen up the bracket where it attaches to the playfield so it can move a little until you find the sweet spot.

Are you sure you have the bushing on the motor pin? It's easy to lose.

If the bushing is there, are you sure the visor actuating rods are not bent?

///Rich

Rods aren’t bent and bushing is there
I will take a photo.
Unfortunately I have plenty of time to get his figured

Ok got it all together. Visor sits properly.
I was test plying it and the only
Complaint is the upper left saucer( the one to the left of the visor ) is a tuff shot. It bounces at some of the time. Is that a tuff shot or do I need a cushion on the deflector

I have the same problem on my Taxi with the Jackpot/Gorbie shot. Annoying when I drill the Jackpot and it doesnt count. I've thought about putting a thin rubber pad for cabinet doors on the deflector. Not sure though.

Do you thin the deflector need to be bent forward or is It the angle.

Its driving me nuts
Is this the correct deflector ?

image (resized).jpg

Here’s another view

image (resized).jpg

That looks right.
Is the round metal Cliffy protector not lined up exactly right, or the inside diameter of it too small?
Cliffy protector should not cause a problem, but definitely not factory.

Anyone know where you can purchase these target faces under the visor? I don’t need the complete switch, just the faces.
Thanks

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