(Topic ID: 66476)

Voltages too high on Bally Paragon Rectifier Board


By Gorgared

7 years ago



Topic Stats

  • 17 posts
  • 6 Pinsiders participating
  • Latest reply 7 years ago by barakandl
  • Topic is favorited by 3 Pinsiders

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#1 7 years ago

Hopefully someone can help. I have a Bally Paragon I'm working on and the voltages are too high on the rectifier board. I have rebuilt the reset circuit on the MPU (acid damage) and installed new proms/roms (I jumpered the board correctly, I have checked and rechecked). I also rebuilt the rectifier board with all new components. The MPU does 6 flashes, but I can't get it do the 7th.

I installed a known working rectifier board and transformer into the machine and got nearly the same voltages, so I have ruled out those components. I am out of ideas though and any help would be appreciated.

Here are the voltages (all connectors attached to game):
TP1: 6.42 VDC - Should be 5.4 VDC
TP2: 258 VDC - Should be 230 VDC
TP3: 15.08 VDC - Should be 12-14 VDC
TP4: 7.13 AC - Should be 5.7 to 7.3 AC
TP5: 54.5 VDC - Should be 43 VDC

Here are the voltages with J2 only connected to the Rectifier board (isolated from the rest of the game):
TP1: 6.44 VDC - Should be 5.4 VDC
TP2: 186 VDC - Should be 150 VDC
TP3: 13.16 VDC - Should be 13-16.5 VDC
TP4: 7.45 AC - Should be 5.7 to 7.3 AC
TP5: 46.3 VDC - Should be 43 VDC

Any ideas what I should check next?
Thanks!

#2 7 years ago

With J4 connected on the MPU what do you have at TP3 on the MPU?

#3 7 years ago

Check to see how the xformer is tapped. There is labels usually right nearby indicating settings. Maybe it is set for 110v.

#4 7 years ago
Quoted from Marc:

With J4 connected on the MPU what do you have at TP3 on the MPU?

TP3 on the MPU is 26.1 VDC, it looks like it should be 21.5.

Quoted from barakandl:

Check to see how the xformer is tapped. There is labels usually right nearby indicating settings. Maybe it is set for 110v.

The machine is set for 115V. It can be set to 120V as well according to the manual. I will check my wall voltage and see what it is.

#5 7 years ago

Are you sure your meter is working correctly? If so i would go ahead and set it for 120v if you can easily change the pins around in the connector.

MPU TP3 should be half of what the 43v line which it basically is.

No 7th flash, make sure the R113 and R16 are not burned (they are probably okay if you correct at TP3)

Check IRQ line that goes from u9 CPU to both pias and look for a short or lack of continuity.

Try a new U10

Check to make sure zero crossing circuit at U14 is working correctly. Start at the PIA U10 P18 and look for a low pulse(i think bally says 1/4 vdc). If you are missing that work back wards towards u14. Bally was nice and wrote the voltages in the schematic in this section, follow through and check each one.

#6 7 years ago

TP3 is what the MPU is reading to verify you have solenoid power and gives you the seventh flash. It is a little high but I would think it should still boot.

*EDIT* ^^^ beat me by 4 seconds...but had a much better explanation.

#7 7 years ago
Quoted from Gorgared:

Hopefully someone can help. I have a Bally Paragon I'm working on and the voltages are too high on the rectifier board. I have rebuilt the reset circuit on the MPU (acid damage) and installed new proms/roms (I jumpered the board correctly, I have checked and rechecked). I also rebuilt the rectifier board with all new components. The MPU does 6 flashes, but I can't get it do the 7th.
I installed a known working rectifier board and transformer into the machine and got nearly the same voltages, so I have ruled out those components. I am out of ideas though and any help would be appreciated.
Here are the voltages (all connectors attached to game):
TP1: 6.42 VDC - Should be 5.4 VDC
TP2: 258 VDC - Should be 230 VDC
TP3: 15.08 VDC - Should be 12-14 VDC
TP4: 7.13 AC - Should be 5.7 to 7.3 AC
TP5: 54.5 VDC - Should be 43 VDC
Here are the voltages with J2 only connected to the Rectifier board (isolated from the rest of the game):
TP1: 6.44 VDC - Should be 5.4 VDC
TP2: 186 VDC - Should be 150 VDC
TP3: 13.16 VDC - Should be 13-16.5 VDC
TP4: 7.45 AC - Should be 5.7 to 7.3 AC
TP5: 46.3 VDC - Should be 43 VDC
Any ideas what I should check next?
Thanks!

None of those voltages are really out of acceptable range.
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#8 7 years ago

Those voltages look fine. What do the DC voltages look like on the test points on the other boards, post rectifier & filtering? Pictures may us help you as well.

#9 7 years ago
Quoted from barakandl:

Are you sure your meter is working correctly? If so i would go ahead and set it for 120v if you can easily change the pins around in the connector.
MPU TP3 should be half of what the 43v line which it basically is.
No 7th flash, make sure the R113 and R16 are not burned (they are probably okay if you correct at TP3)
Check IRQ line that goes from u9 CPU to both pias and look for a short or lack of continuity.
Try a new U10
Check to make sure zero crossing circuit at U14 is working correctly. Start at the PIA U10 P18 and look for a low pulse(i think bally says 1/4 vdc). If you are missing that work back wards towards u14. Bally was nice and wrote the voltages in the schematic in this section, follow through and check each one.

Thanks for all the help so far guys.
I switched my transformer over to 120v from 115v since my wall voltage was 123v. That brought down the voltages slightly.
Here are the voltages (all connectors attached to game):
TP1: Was 6.42 VDC is Now 6.05- Should be 5.4 VDC
TP2: Was 258 VDC is now 246- Should be 230 VDC
TP3: Was 15.08 VDC is now 14.26 - Should be 12-14 VDC
TP4: Was 7.13 AC is now 6.8 - Should be 5.7 to 7.3 AC
TP5: Was 54.5 VDC is now 51.8- Should be 43 VDC

R113 and R16 are reading normal resistance.

I checked IRQ line from u9 to the pias, it is ok.

Tried 2 different U10 chips, didn't work.

I hooked up my logic probe and got a low voltage pulse from U10 Pin 18.

Quoted from thedefog:

Those voltages look fine. What do the DC voltages look like on the test points on the other boards, post rectifier & filtering? Pictures may us help you as well.

I took voltage readings after switching the transformer to 120v
MPU:
TP1: 5.15 vdc - should be 4.9 to 5.2
TP2: 14.13 vdc - should be 12-14
TP3: 25.2 vdc - should be 21.5
TP4 ground
TP5: 5.15 vdc - should be 4.9 to 5.2

Solenoid driver board
TP1: 5.19 vdc - should be 4.9 to 5.2
TP2: 185.7 - should be 190
TP3: 5.12 - 4.9 to 5.2
TP4: 250 vdc - should be 230
TP5: 14.18 vdc - should be 12 to 16.5

Lamp driver board
TP1: 5.21 vdc - should be 4.9 to 5.2
TP2 ground

So it's still not working. I'm thinking about soldering in a new U10 socket? Should I?
Any other ideas or things to check?
Thanks for all the help so far!

#10 7 years ago

If you have a low pulse on the PIA zero crossing pin. In theory the zero crossing circuit should be working correctly. So i am kind of at a loss. I don't think the overvoltage on the 43v line is going to cause zero crossing not to work. Try disconnecting the sound board. The sound board uses the 43v line and it ramps up the voltage on its board. There is a blocking diode on the sound board that should not allow it to leak back into the 43v line, but it can fail.

Still double check u14. Look for low pulse at U14 P4 and P15. High pulse (inverse of prev) at P10, P14.

A bad PIA or socket should be caught by pia test flash #4, U10 is tested sans P18 for zero crossing during the 4th flash. A floating input/output from a bad socket wouldn't stop the 7th flash unless it is zero crossing CB1 line P18.

Maybe the MPU is not selecting U10 properly. I suppose U18 or U19 could cause your problem, but i would think unlikely. Check u18D for inverting signal. Check U19C and U19D. Looks like A7 involves chip select for u10.

#11 7 years ago

You're the man! I unplugged the sound board and the machine fully booted. Do you know the diode # on the soundboard that failed, I know I will find it but if you know it off the top of your head that would help me out. Thanks again!

#12 7 years ago

CR3 on the sound board is probably shorted.

Happy i could help = )

#13 7 years ago

CR3 was bad. I replaced the diode and reflowed the solder on the sound board pins and it fired right up! I still have a few more issues but I should be able to figure them out. If not, I know who to ask!

Thanks again everyone, especially barakandI.
I don't know if I would have figured it out by myself.
Pinside rulez.

#14 7 years ago

So after getting the machine to boot up, I am having a few more problems. My start button will not start a game. I have traced the wires up to J3 connector on the MPU and they are fine. I can start a game by grounding the red wire on the start button. Once the game starts the first player score will score but then reset to zero while the game is playing. It will count up a bit, then reset to zero over and over. I also noticed when I add credits to the game I will click it numerous times and it will stay at 1 credit, then sometimes it will count the credits up but will then reset back to 1 credit. For example, I'll add 3 credits and the 4th it will go to 2, then 3, then 4, but instead of 5 next, it will reset back to 1 credit.

I am going to re-pin the J3 connector on the MPU, but I have to order the parts. Any ideas what else it could be, besides possibly J3?

#15 7 years ago

Check the .093 connector block that connects the harness at the coin door.

#16 7 years ago

I figured out what was going on with the Paragon machine (with help from barakandI, thank you!). It turns out it was a bad 5101 RAM at U8 on the MPU board. I had put in all brand new chips on the MPU board, so I didn't really suspect that at all. Turns out not all "new" chips are functioning!

Hope this helps someone in the future.

#17 7 years ago

Yay.

5101s are very sensative to static damage. A bad one sometimes slips past the power on self test and causes all sorts of odd issues.

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