New! Dark mode!

Browsing Pinside at night? Getting tired of all the white? Switch to dark mode using the button in the top right (or CTRL-B)!

(Topic ID: 177684)

Bally MPU only 6 flashes... No voltage at TP3

By MrBellMan

3 years ago

Topic Stats

  • 12 posts
  • 8 Pinsiders participating
  • Latest reply 1 year ago by ChippyWonka
  • Topic is favorited by 5 Pinsiders


Linked Games

Topic Gallery

There have been 3 images uploaded to this topic. (View topic image gallery).

2018-03-04 21.51.18.jpg
IMG_2561 (resized).jpg
MPU (resized).jpg

#1 3 years ago

Checking to see if anyone has run into this issue...

I have a Bally MPU that when I boot that game I only get 6 flashes… I have 43 volts on the side of R113 closest to J4, but no voltage at TP3. I have looked through all of the guides, verified the resistors are not closed, disconnected the sound card, etc…

The missing voltage at TP3 is what has me stumped! No battery damage and NVRAM installed.

Any ideas?


Rob Bell

MPU (resized).jpg

#2 3 years ago

R113 is probably open circuit. It's fairly common.

#3 3 years ago


I agree with above. R113 (CR52 since it is a baby pac MPU) is probably open circuit. Replace it and R16 with 1/2w 2K ohm resistors.

ALSO your R11 looks burnt. Since you are using NVRAM.... Cut out R11. Replace nearby glass signal diodes CR5 and CR7 with zero ohm jumpers (or just jumper over top the diode). That saves you from using that stupid R11 circuit to drop 12v down to 5v for U8. NVRAM does not need to be on the 12v rail.

#4 3 years ago

Thanks for the feedback! I'll tackle this early next week and report back!

#5 3 years ago

Also make sure you upgrade your Voltage Regulator / Sol. Driver board.
Do the ground updates and 5V fix.
While you have the board out, solder the print headers.

#6 3 years ago

Sure enough the circuit was open! Replaced components (had to use 1/4 watt resistors), jumped CR5/CR7 and now I get my 7th flash and game play!

Thank you all very much for the assistance!

Rob Bell

IMG_2561 (resized).jpg

3 months later
#7 3 years ago

Wow, you guys are awesome! I just picked up a project Strikes and Spares last week with the exact same symptom of no voltage on TP3. I tested R113 and it was open. So, I robbed R113 off of one of my dead boards and replaced it. Kapow! It booted right up and the game works great! Thanks to you all for posting this helpful thread!!!

10 months later
#8 2 years ago

Bally paragon same issue 6 flashes. Can I jump cr5 / cr7 on this game also? I noticed some corrosion at r12 also and I am addressing that

2018-03-04 21.51.18.jpg

#9 2 years ago
Quoted from Michigankid:

Bally paragon same issue 6 flashes. Can I jump cr5 / cr7 on this game also? I noticed some corrosion at r12 also and I am addressing that

Jumpering CR5 and CR7 is only for when you are using NVRAM at U8. It does not fix anything with the TP3 voltage.

First and foremost you need the 43v for the 7th flash and voltage at TP3. Can you check to make sure your rectifier fuse for the solenoid 43v is not blown

4 weeks later
#10 2 years ago

Thanks guys it was the 2k resistor on the 43v circuit.

1 year later
#11 1 year ago

Same here!
Another fixed MPU!
The thread that keeps on threading!

5 months later
#12 1 year ago

Just used this thread for my Spy Hunter mpu. Thanks!

Promoted items from the Pinside Marketplace
$ 149.95
From: $ 14.00
Third Coast Pinball
From: $ 45.00
From: $ 155.00
Machine - Wanted
Shoreline, WA
$ 9.00
Cabinet Parts
Third Coast Pinball
$ 10.00
Yorktown Arcade Supply
From: $ 155.00
$ 30.00
Third Coast Pinball

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside