(Topic ID: 167508)

Mata Hari Transformer and Rectifier Board Issues


By QuietEarp

3 years ago



Topic Stats

  • 25 posts
  • 6 Pinsiders participating
  • Latest reply 3 years ago by QuietEarp
  • Topic is favorited by 4 Pinsiders

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#1 3 years ago

Hi, I am trying to bring a Mata Hari Solid State back from the dead. When I got it it was missing all boards except for the Power Supply and transformer. All fuses were intact at this time.

I got the Alltek MPU board, Solenoid Board, and Lamp Driver Board, so I figured I would test the voltages at the test points on the rectifier board before hooking those boards up.

I plugged the machine in and fired it up. The only connector plugged into the power supply was J2 from the playfield. Fuse F6, 3 amp, blew almost immediately. I replaced the fuse and it blew again.

Where should I start troubleshooting this? I am handy with a multi-meter. Is there a way to isolate and test the transformer? Could the bridge rectifiers be at fault? I am more than ready to get this machine running!

Thanks!

#2 3 years ago

You should start here:

http://www.pinwiki.com/wiki/index.php?title=Bally/Stern#Bally

F6 is your Mains AC input to the transformer.

When you say "power supply" you mean the rectifier board?

Remove ALL fuses except F6. Does F6 still burn?

The game may be a repatriated export and needs to have the transformer re-strapped (jumpered) for domestic use.

#3 3 years ago

I edited original post to change "power supply" to rectifier board.

Transformer is set up for 115volts, I verified the wiring.

I removed all fuses but F6 and no fuse blew. Transformer was also much quieter. That is a good sign. What did I learn? Would this point to a bridge rectifier? If so can those be tested in circuit or must I remove them? What did I learn?

#4 3 years ago

By removing all fuses except F6 (AC Mains IN) you have isolated the transformer from the rectifier. The fact that F6 now survives indicates the transformer and wires to the rectifier are not shorted somewhere.

Now you need a 3Amp Circuit Breaker, or a handful of 3A SLO-BLO fuses.

With only F6 installed, power up game. The fuse should survive if I understand correctly. Power down.
Install F5. Power up. If both fuses survive, now you will have visual confirmation if the game is actually a ON or OFF.

Now continue replacing the fuses with the correct rating with power off each time.

You should run into one that pops the Mains again.

Let us know what your investigation reveals.

#5 3 years ago

Sounds like a plan. I have at least 4 more fuses on hand.

Could this be accomplished by testing the bridge rectifiers or circuitry? Anyway, that was a good sign for the transformer.

Thanks cody_chunn.

#6 3 years ago

OK, I did as cody_chunn described and replaced the fuses one at a time.

F2 3/4 amp fuse is the culprit. When that fuse was installed F2 blew. I believe there may have been a larger fuse installed in F2 when I initially turned the machine on (I know, I should have verified this before starting the machine). Maybe this is why F6 was blowing instead of F2 initially.

Now where should I look? The schematics seem to point to CR1-CR4 (I think these are diodes, but I don't have the machine in front of me as I need to go to bed).

What do you think?

#7 3 years ago

There're 1n4004 diodes - cheap and easy to install.

#8 3 years ago

Using a DMM on diode test, see if the diode is shorted. You could also pull the rectifier plug that goes to the head. If the 3/4a fuse still blows, the diodes Bob mentioned are probably shot.

Use 1n4004 or better, I usually sneak the next size up diode in there for good measure, they fit OK.

#9 3 years ago

Cool, I will give this a shot when I get home. Do I have to remove diodes to test them? Seems like I would.

Quoted from barakandl:You could also pull the rectifier plug that goes to the head.
The only thing plugged into the rectifier board at this time is the cabinet which has the AC power coming in.

#10 3 years ago
Quoted from QuietEarp:

Cool, I will give this a shot when I get home. Do I have to remove diodes to test them? Seems like I would.

The only thing plugged into the rectifier board at this time is the cabinet which has the AC power coming in.

You can test these in circuit. DMM on diode test. One direction you should get infinity "OL". The other direction 0.400v to 0.6v. Diode that blows the fuse will read 0.00 in both directions.

#11 3 years ago

OK, I found the culprit. Bad Diode CR4. Replaced it (found one in the bottom of my tool box!) and now no fuses blow. Test voltages came back a little low on TP 2 and 3. Is this because it rectifier is the only board connected? I want to make sure it is good before adding those new boards $$$.

TP1 6.6V OK, TP2 184V (should this be 230?), TP3 6.4V (Should this be 11.3?), TP4 7.5VAC OK, TP5 47V OK.

I also seem to be missing the ground braid from Cabinet to Backbox

#12 3 years ago

You should connect the backbox to ground - it's also a safety thing.

TP2 is probably OK - this runs the score displays. Check the high voltages on the driver board after it's installed.

TP3 may be a problem - you need good voltage here. Are you sure you're checking on DC not AC?

#13 3 years ago

Unloaded supply voltages do not read properly a lot of times with a dmm.

TP3 is the 12v supply and I'd expect to see higher than normal voltage, not under. Hard to predict. Safe enough to plug in the solenoid driver board top right plug and then check voltages on the solenoid driver board.

#14 3 years ago

I made a temporary jumper with some #6 stranded wire to connect backbox to ground, I noticed that when looking for a place to put my probe. Can't find the braided wire, maybe someone removed it?

Definitely checked DC, not AC.

I am going to fix the main AC cord tomorrow (it just looks pretty janky) and give it a shot on barakandi's recommendation.

In the schematics after TP3 I see it connects directly to J3-8 which is labeled To REG (+5) Input. Am I right in thinking that this means my reading of 6.4 is correct for an unconnected board?

Thank you guys for the help!

#15 3 years ago

The #6 wire will be fine for the ground strap.

The TP3 voltage will vary wildly depending on what is connected. But like Andrew said it usually shows high with nothing connected. I've seen it as high as 20 volts with nothing connected but it came down after the driver board was connected. It also depends on your DMM.

The TP3 supplies voltage to the regulated 5 volts on the driver board but it also supplies 12 volts to the MPU.

I'd go ahead and connect J3 on the driver board and check TP5 and TP1. Leave the MPU unconnected for now.

#16 3 years ago

Alright, I replaced the AC cord with a better one and plugged in the Solenoid and Lamp driver board, no MPU yet. Turned the game on and the backbox lit up! Life! I checked voltages and they were all within spec except for TP3 which was 17 volts. The lights on the Alltek solenoid board are doing their happy dance.

Quoted from oldschoolbob:

The #6 wire will be fine for the ground strap.
The TP3 voltage will vary wildly depending on what is connected. But like Andrew said it usually shows high with nothing connected. I've seen it as high as 20 volts with nothing connected but it came down after the driver board was connected. .

So what do you think? Time for the MPU?

What I think I have learned is that TP3 tests around 6 volts with nothing connected but the rectifier board, and then tests higher than 12 volts after the solenoid driver board gets connected. Should come down to spec once the MPU is connected. Sound right?

Thanks for your help guys! Want to put that playfield in and then get my rubber rings in the mail!

#17 3 years ago

I'm not familiar with the Alltek boards but if the voltages check out on the solenoid driver board it's time to plug in the MPU.

#18 3 years ago

Unregulated 12 runs like 12-18v typically. I have no clue how bally came up with 11.9v for that supply voltage...

#19 3 years ago

Cool. I put it all together and so far so good. I have to do a little more work on the playfield and get the rings and plastics put back on. I also need a new fuse holder for the playfield.

I turned it on and heard the chimes! I am not sure I have the MPU set up correctly and was trying to add credits, but was not sure how it was set up or mangled from its previous life. Without a fuse on the playfield it is hard to tell what is going on.

I am on vacation for a week or so so will have to shelf this project for a while. Thank you to all who helped me in this thread! I am considering this one closed as the Transformer and Rectifier board are definitely working!

Thank you again!

#20 3 years ago

If you hear chimes, the MPU is booting up. good times ahead.

#21 3 years ago

If only there were more of those reproduction playfields available! Seems like I hear of lots of people wanting one. I could sure use one.

When I got this machine it seemed like a good thing, it was part of a bigger trade, but buying $500 worth of boards and parts and making a $700 machine out of it makes me question my sanity. It is not about the money!

#22 3 years ago
Quoted from QuietEarp:

If only there were more of those reproduction playfields available! Seems like I hear of lots of people wanting one. I could sure use one.
When I got this machine it seemed like a good thing, it was part of a bigger trade, but buying $500 worth of boards and parts and making a $700 machine out of it makes me question my sanity. It is not about the money!

That's the problem with the older machines; they make zero sense to restore like this financially, but if you like the game.....

#23 3 years ago

Money well spent. I've been there too. Congrats on the progress. Mata Hari is a great machine.

#24 3 years ago
Quoted from Tickerguy:

That's the problem with the older machines; they make zero sense to restore like this financially, but if you like the game.....

Learn how to fix the originals.

I started out by buying dirt cheap bally games. I couldnt afford to just buy new boards, but i was determined to play. I found a way to fix the originals, took a lot of effort tho and i had fun along the way.

#25 3 years ago

I would have fixed the originals, but the game came without any (except the old rectifier board of course). Once I had to purchase an old probably broken board to fix up, buying the new ones started to made sense in a weird kind of way.

I had a Paragon and fixed up the lamp driver board and solenoid board in that one.

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