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Author Topic: Pacman transformer bad?  (Read 5013 times)
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akaclarkkent
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« on: September 03, 2015, 10:09:16 am »

Hi everyone, new to forum, long time John's view, and recently 1st time arcade owner/restore project.

My original upright Pacman "was" working. I have been doing the update to fuse blocks and edge connector. Prior to starting this I checked the voltage out of the transformer and was getting both 12V and 7V it was suppose to give. Now, after doing some work on fuse blocks and replacing fuses I am getting the following voltages 3.8 (instead of 12) 2.0 (instead of 12) 1.8 (instead of 5) and 0 (instead of 5). I have 120volts going into transformer. Also these volts are tested at transformers terminals themselves and not at new fuse blocks or solder joints so my work, good or bad, is not yet in the equation. Did my transformer go bad all the sudden? Is there anything I should check prior to AC entering transformer? There is no board connected and monitor was unpluged so is not under load.
Thanks for any help.
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iankellogg
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« Reply #1 on: September 03, 2015, 03:45:36 pm »

sounds like you wired up the transformer wrong. I would recheck all of your wiring
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akaclarkkent
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« Reply #2 on: September 03, 2015, 07:39:03 pm »

sounds like you wired up the transformer wrong. I would recheck all of your wiring

Thanks for reply Ian. Problem is I didn't wire it, de-wire it, or touch it. I replaced fuse blocks after it's output. And I'm testing on the transformer itself. Which is giving same low readings I am getting past fuse blocks I replaced anyway.
The pacman transformer has wires for 117volts in, which gives 122 reading. O in and E in. Both those read zero. But outputs are too low at its tabs and I didn't solder or de-solder anything on input or output transformer tabs.
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iankellogg
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« Reply #3 on: September 03, 2015, 07:50:17 pm »

The fuse blocks feed the transformer. It's worth checking everything again
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akaclarkkent
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« Reply #4 on: September 05, 2015, 05:35:24 pm »

The fuse blocks feed the transformer. It's worth checking everything again

Thanks again for reply Ian. I've tested more and have more information to offer:
With game plugged in but power switch off I get 120vac intotransformer and iso Transformer. No output on iso trans and 2vac output from transformer to fuse blocks.
With game turned on Iso transformer to monitor only giving off 60 volts. Voltage out of power transformer to game actually drops even lower on the two 12vac.

edit:Marquee light comes on when switched on. No other wires changed or hacked.
Using new power cord from bob Roberts. Using old cord that 120 reading only 60vac.
 
Could this be bad ac line filter? Ac line fuse block was changed and working.
Could this be a dead short? If so would it be off fuse blocks or daisy chain to iso ?
« Last Edit: September 11, 2015, 10:58:42 am by akaclarkkent » Logged
iankellogg
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« Reply #5 on: September 14, 2015, 09:57:54 am »

I really dont know how to explain what I would do. I still think there is something wrong with the wiring. Your best bet is going to be downloading the manual for pacman. follow the wiring diagram and test every voltage exactly as its written in the manual. If you dont have the correct voltage make sure you have the correct wire hooked up for the primary winding and if needed turn the game off and do continuity tests with the windings to make sure they are good.
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akaclarkkent
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« Reply #6 on: September 14, 2015, 10:45:46 am »

Power is fixed. Thanks Ian and Madrit for the help. Stupid new mistaken. I have zero experence with arcades and mulimeters. When testing AC off the transformer I would use black lead of multimeter on any ground I could find and not on one directly beside transformers output for 12vac, and then the one for 7. Same problem for isolation transformer. Unless I tested AC using both top terminals my readings were off. I just didn't know how to test properly.
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iankellogg
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« Reply #7 on: September 14, 2015, 10:47:01 am »

I had a feeling that was the case but i really don't like insulting people assuming they don't know how to use a multimeter.
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akaclarkkent
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« Reply #8 on: September 14, 2015, 10:53:02 am »

No insult hear. You, John, the forum are my help. I just have to trial and error and watch and read since I have no local help. I'm thankful. And Learning so all is good.
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