(Topic ID: 142490)

Help with Stern Galaxy Please

By dbpbandit

4 years ago

Topic Stats

  • 11 posts
  • 5 Pinsiders participating
  • Latest reply 4 years ago by hawkmoon
  • Topic is favorited by 3 Pinsiders


Linked Games

  • Galaxy Stern Electronics, 1980
#1 4 years ago

I'm working on a basket case here and I need some help please.

I rebuilt the Rectifier board, everything looks good however I'm getting test voltages that are off.

Test Results:

TP1 = 6.25 VDC (good)
TP2 = 149.1 VDC (to low)
TP3 = 20.4 VDC (to high)
TP4 = 6.7 VAC (to low)
TP5 = 44.6 VDC (to low)

Some of these are off by a lot, any suggestions?

FYI, I am testing voltages on the bench.

Thank you

#2 4 years ago

You will get crazy readings on an unloaded unregulated power supply. Get your solenoid board hooked up and retest.

#3 4 years ago

So I plugged in my solenoid driver board (now it's just the rectifier and solenoid driver) and I'm still getting basically the same readings. However, TP4 on the driver board has no voltage si I figure something is wrong with the high voltage section. But, the large sand resistor on the rectifier gets really REALLY hot. Why would this be happening? Am I shorted somewhere?


#4 4 years ago

The only voltage that's far enough off to be a concern is the HV. TP3 should have dropped closer to 12 volts with the SDB hooked up. TP1 is a little high but should get regulated by the SDB. You actually look pretty good where you're at on the rectifier sans the HV.

Those sand resistors are high-wattage components that dissipate a lot of heat. They get really hot.

#5 4 years ago
Quoted from cody_chunn:

Those sand resistors are high-wattage components that dissipate a lot of heat. They get really hot.

Yep. In the wild world of pinball service, you never want to lean your hand on those ceramic resistors.

They get so hot, they sometimes unsolder themselves from the boards!

#6 4 years ago

Yeah, I was gonna mention those snubbers or whatever they are that drive WMS flashers that unsolder themselves and drop onto the cabinet bottom. "Now where did THIS thing come from?" Apparently route techs asked that question and answered: "The trash can, obviously! Duh!"

2 weeks later
#7 4 years ago

More help pleas! So I installed a new Rotten-dog power board and a new ultimate MPU but I still can't get it to boot. My voltage at the MPU test point 4 is way to high. I have the +5 so it must just be wired wrong? Can someone give me the pin-out of the J4 connector? Not the board but the cable, I think the previous owner screwed with it. Thanks.

#8 4 years ago

MPU needs +5v, +12v and +21v (half of solenoid voltage) to boot up. Ignore mpu TP4 for now. Make sure the 21v test point is there or you will not get the 7th flash.

#9 4 years ago

which pins on J4 carries what voltage?

#10 4 years ago

The ones closest to the bottom of the plug. Follow the traces to tp2,tp3 and tp5. Schematic page has them labeled as well.

#11 4 years ago

The manual for this game is still available,i have to reference mine sometimes!!!

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