(Topic ID: 228758)

Paragon problems with voltages and no booting - Solved


By buffaloatx

8 months ago



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  • 15 posts
  • 4 Pinsiders participating
  • Latest reply 8 months ago by oldschoolbob
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Voltage_WaveformsA.jpg

#1 8 months ago

Hey everyone! Need a spot of help figuring out what's going on with a friends Paragon.
The back story, a GPE rectifier board and Altek MPU were in this game and it worked properly for two years. No work was done to it, and it was not moved recently.
One day one of his kids turned it on and it just didn't boot.

The only problem's I found were TP3 the 12v was only putting out 10.2v and the MPU and Solenoid Driver were only getting 4.1-ish volts, and R1 was hot, like almost dangerously hot (I know resistors get hot, but this one was almost hot enough to actually burn you)
I was getting flaky readings on BR2 so I replaced it with a higher voltage rectifier with the same amperage (600v-35amp). Plugged everything back in and still got only 10.2c at TP3.

Like a dummy I forgot to check the resistance of R1 while I was there, but since it deals with the 48v I kind of figured it was not directly tied to this problem.

So, where should I go from here?

* ok, so I just read that this resistor may get up to 200 degrees F on the GPE schematics so never mind that...

#2 8 months ago

Sounds like capacitor C23 on the solenoid driver board isn't functioning either due to failure or probably because its negative lead that connects back to the rectifier board has lost connectivity. Check the wire terminals of the white-brown wire at pin 10 of J3 of the solenoid driver board and pin 17 of J3 of the rectifier board. Re-terminate if either are bad.

As extra redundancy there's some mods for the solenoid driver board which one caters for this weak point:
http://www.pinwiki.com/wiki/index.php?title=Bally/Stern#Solenoid_Driver_Upgrades

#3 8 months ago

Thanks quench I'll see if the owner can trace that out and report back ASAP.

#4 8 months ago

Agree with Quench, especially If the game has the original filter caps on the Solenoid driver they should be replaced.

#5 8 months ago

Sorry for the delay, tested J3-p10 to J3-p17 and got a good tone. The connectors all look good, and the cap was replaced last year. I'm waiting to see if he can test the cap in circuit to get a rough idea if it is failing with his DMM while I wait for my new ESR meter to arrive.
I'm still concerned that the 12 volts form the rectifier board is only outputting 10.02 volts and were only getting 4.2 volts from the regulator. He has a replacement regulator, but I don't want to mess with that unless absolutely necessary.
Thanks!

#6 8 months ago
Quoted from buffaloatx:

Sorry for the delay, tested J3-p10 to J3-p17 and got a good tone.

Using your multimeter tone as a guide for continuity can give you false readings. Multimeters will give a tone sound even when there is up to 150 ohms of resistance. You need to set the multimeter to resistance mode and look for zero ohms readings when checking continuity.

Quoted from buffaloatx:

I'm still concerned that the 12 volts form the rectifier board is only outputting 10.02 volts

The voltage at TP3 on the rectifier board (with the head (J3) disconnected) looks like point Q below. When you connect J3 to the rectifier board and it applies capacitor C23 from the solenoid driver board onto the 12V supply rail, it will now look like point R. That capacitor stores energy and raises the average voltage on that supply rail. Since you're getting a low voltage there, it looks like C23 is not connected or faulty so is unable to filter that 12V supply rail which is causing excessive ripple on the input to the regulator. The ripple is causing drops to zero volts during the voltage phase (as you see in point Q) resulting in the regulator output being low. The voltage regulator needs a voltage on the input that is at least 2 volts above its output voltage rating and it must never drop below this in order for the regulator output voltage to be stable.

Even if C23 was properly connected and working and you were still only measuring 10 volts, it's still a high enough input for the voltage regulator to output 5 volts.

If you disconnect connector J3 from the rectifier board, what voltage do you measure at TP3 on the rectifier board?

Voltage_WaveformsA.jpg

#7 8 months ago

Thanks quench this is a lot of great information. If I remember correctly I did measure TP3 on the rectifier board with J3 disconnected and it was still 10 something volts (I'm not 100% sure what it was, it was similar to the connected 10.2 volts, but not exactly the same, may have been 10.5or7 volts)
Unless you think I should go a different route I'll replace the cap and possibly reinforce the ground return as recommend in your earlier post.

It is probably going to take me a while to get back to his place as my real job is getting busy for the holiday season, and he lives about 60 miles from me (which in Texas is almost next door), but I'll update as soon as I can.

#8 8 months ago
Quoted from buffaloatx:

If I remember correctly I did measure TP3 on the rectifier board with J3 disconnected and it was still 10 something volts (I'm not 100% sure what it was, it was similar to the connected 10.2 volts, but not exactly the same, may have been 10.5or7 volts)

That pretty much tells me the problem is around capacitor C23. A functioning C23 capacitor will bring that 10VDC up to just over 14VDC as it removes most of the ripple and flattens out that supply rail.
Another way you can check is to measure the AC voltage at TP3. If it's around 10 volts AC, then C23 is not filtering that supply rail. If it's around 0.2VAC then C23 is doing its job.

Quoted from buffaloatx:

Unless you think I should go a different route I'll replace the cap and possibly reinforce the ground return as recommend in your earlier post.

I'm big on diagnosing faults before replacing parts. Measure the voltage directly across the legs of capacitor C23 - black meter lead on the negative capacitor leg, red meter lead on the positive capacitor leg. If you measure 10 volts, then the capacitor is connected in circuit but has malfunctioned - would be strange for a cap that was replaced a year ago. If you measure substantially less than 10 volts there is an open circuit (probably ground) to the capacitor.
You can also do the AC voltage measurement I just mentioned in the previous paragraph.
For reference, the ground mod for C23 can be seen here in vid1900's guide:
https://pinside.com/pinball/forum/topic/vids-guide-quick-bally-driver-board-repair-bulletproofing#post-592759
The other two recommended mods for the solenoid driver board are shown around that post.

Just note, with electrolytic capacitors, smallest physical size does not equal better. They overheat quicker which results in shorter life span.

#9 8 months ago
Quoted from Quench:

Just note, with electrolytic capacitors, smallest physical size does not equal better. They overheat quicker which results in shorter life span.

This is why I think the cap may be failed/failing it's a 25v 11,000uf cap, but is really small. I'll report back after I get my hands back on the game. Thanks again for all the help.

#10 8 months ago

Success. I got the board from the owner replaced c23 with a 35v 15000 uf cap (I know it's a bit higher rated than spec, but I've seen them used on this board before). I also tied the grounds together as suggested earlier.
I used my Spy Hunter to test the repair. Plugged the board in with the MPU disconnected and powered it up. I am now getting 5.12 volts. at both 5 volt test points (TP1&3)
Powered down and reconnected the MPU to test game boot and functionality. MPU boots, displays work, sound works, YAY! Start a game, flippers work, switches register, but I have no other coils working, BOO!
Swap in my board (which was working the last time I played it a few months ago) same result, no coils except flippers (well the knocker works and the coin door relay coil work).
Since both boards are acting the same way I'm assuming the the issue is somewhere else in the game. I'll get to that at some point soon.
quench thank you.

#11 8 months ago
Quoted from buffaloatx:

Start a game, flippers work, switches register, but I have no other coils working, BOO!

Check the 1 amp slow blow fuse under the playfield near the flipper mechs. That fuse is for all the playfield coils *except* the flippers.

BTW, I use a 15,000uf cap at C23 on the solenoid driver board too.

#12 8 months ago
Quoted from Quench:

Check the 1 amp slow blow fuse under the playfield near the flipper mechs.

Yup, totally blown. Somehow missed that fuse while I was checking every other fuse in the game.

Thanks again Quench. I'll mark this as solved.

#13 8 months ago

What would cause that fuse to blow? I had the same think on my Meteor the other day.

Couldn't find any bad coils.

Thanks

Bob

#14 8 months ago
Quoted from oldschoolbob:

What would cause that fuse to blow?

You've got suspect power stability issues with that Meteor right? What's the chance the MPU locked up and a coil locked on? Is there any suspect wiring on a coil? Did you notice what the last solenoid was that activated around the time the fuse blew and all other coils stopped working?

#15 8 months ago

Thanks Quench,

I do have power problems with that game. I suspect it's with that Rottendog solenoid driver board. (I just don't trust that board) I was going to change the SDB for an original board when I discovered the original lost the 5 volts. I've ordered new regulators - LM323's from Jameco and PSUS's from EzSBC. In the meantime I've been working on some new bench work lights.

I didn't notice what was the last solenoid to fire but the owner said it would reset when he used the right flippers. But I don't think the flippers would cause the fuse to blow. So far (after 50 - 60 games) I have only had one reset. And the regulator on that Rottendog gets so hot you can't even touch the heatsink.

After I get the new lights made and the parts arrive I'll be back on the game. Just wanted to give you an update.

Thanks

Bob

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