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(Topic ID: 69219)

need help with a Mata Hari problem...

By DnDPins

6 years ago

Topic Stats

  • 12 posts
  • 4 Pinsiders participating
  • Latest reply 6 years ago by DnDPins
  • Topic is favorited by 1 Pinsider


Linked Games

#1 6 years ago

Here is some of the chronology of what happened:
1) Bought a un-working game and replaced the MPU with an Alltek
2) Rectifier board pins are in bad shape and the wires were soldered directly to them but once I replaced the MPU the game played except the backbox feature lamps; Shoot Again, Ball in Play, etc did not work
3) I had a great time playing about 400 games as is then a drop target broke
4) I fixed the drop target without un soldering anything and reassembled
5) I turned on the game and only got GI lighting
6) Thought I might have blown a fuse so I removed all fuse from the rectifier board and checked. They were all good. Checked fuse under playfield which was good as well
When replacing the fuses, I accidentally inserted F2 fuse between F2 and F3, thus leaving the F2 fuse open and shorting (I suspect) the other. When I turned on the is what happened:
1) Audible buzz, MPU had red LED and Cap on right next to heat sink on solenoid driver board started smoking
2) Turned off the machine and ordered a Rottendog replacement driver board
3) verified all fuses (double checked so as not to make the same bonehead move!)
4) Turned on machine MPU red LED and Driver board Red LED

Is the rectifier board the problem? What do you think the problem with the backbox feature lamps is? I Ordered a new rottendog will install it soon.


#2 6 years ago

What you did is blow the crap out of your game. You ran 160-180v down the 5 volt line likely taking out MPU, driver board and light board. I would expect every 5 volt chip needs to be replaced.

#3 6 years ago

WOW...that is not good news. I was hoping I did not blow my MPU. Is the MPU and light board reparable? What are the next steps to insure things are good before restoring power?

#4 6 years ago

Well he did not run display HV down the 5v line necessarily. It went down the 12v line, which does create 5v. Hopefully the driver board 5v regulator would not end up lighting the voltage on its 5v output from a short on the input to HV. I want to say the regulator's output will go open on a short to HV.

The driver board's 12v/5v regulator section is probably very well damaged. I'd imagine you would smoke the filter caps, the regulator, a couple resistors. No clue if rottendog board is different compared to a normal bally driver board. A normal bally driver board would still be repairable after this kind of situation.

The MPU is likely damaged anywhere that uses the 12v. Reset section and LED circuit.

I would fix the driver board first and see where you are with the MPU.

#5 6 years ago

Just to be clear...the Bally driver board is the one that was damaged. Since then, I made sure the fuses were in the right place, installed the new Rottendog driver board and turned on the machine. The Alltek MPU only has the over voltage red indicator LED on blinks. I do not even get any is like the machine is getting no power.

What is the best way for me to test the Alltek MPU to see what needs to be repaired?

#6 6 years ago

If you had a Bally board i could tell you exactly what to do/check. I have fixed hundreds of normal boards, but never messed with an Alltek.

You want to check your voltages. On a bally MPU TP2 is 12v (you should see maybe 12-16vdc). TP5 is the 5v, you should see 4.75 - 5.25vdc. Check those first.

Since you had a HV short to 12v check the zener diode in the reset section. Check the voltage on each side of the zener. This is assuming Alltek uses a reset section similar to a stock bally, i have no clue what they do to trigger a reset.

#7 6 years ago

Hi barakandl...thanks for your responses!

After replacing the fuses (the Rottendog sol driver board) and turning the machine back on, I blew the F3 fuse. Is it possible that I shorted out something on the rectifier board which is now blowing the fuse or do I have a different problem?

I am have a new Rottendog rectifier board which I am planning on installing. Should I start by replacing the rectifier board? How can I track down what could be causing the F3 to blow?

Thanks again!

#8 6 years ago

One more question...

Since my wires are soldered directly to the old rectifier board, I will be wiring them to new molex connectors when I replace the board. I just want to confirm which is the schematic that details the pin outs going to connectors on the rectifier board?


#9 6 years ago

The schematics on IPDB are correct. Use the wiring diagram for wire colors, use the rectifier schematic for detail on what each wire does. There are duplicate orange wires, so mark one of them.

Perhaps you blew up your bridge rectifier when the fuses shorted. Test the bridges with a DMM.

Also consider just buying a new rectifier board. Sounds like yours has many issues.

#10 6 years ago

The best thing that you could do is follow the Bally guide by clay as to waht to do before turning the game on. It systematically walks you through testing voltages at the rectifier board then the driver board.

#11 6 years ago

I saw someone do this on a Bally Eight ball once. Took out the IC chips on the power/driver board and many chips on the CPU. It was an original Bally CPU and he ended up buying an Alltek for it after I repaired the power driver.

I can see how it can happen since you are essentially plugging in these fuses from the side.

#12 6 years ago

Thanks to all for your responses. PinaballLizard... Is this the Bally guide by Clay?

I have a new Rottendog rectifier board and a connector set so I will be doing that this weekend. Hopefully, I did not fry my Alltek MPU since it has the over voltage protection circuit (one can hope!)

Michiganpinball...I am glad to hear that I am not the only one who has done this. It is very embarrassing! I thought the same thing, it is difficult to install them from the side. I will never make that mistake again.

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