Quoted from Tomass:Hi guys,
I am helping a friend fix a Genie and I am a little stuck. He has all new boards (niwumpf)
But something is off. All the voltages I am reading are about half of what is stated on the transformer. I am testing from transformer terninal lugs to a ground plane in the cabinet. The one all the ground wires run to. At startup, the coil for the drops fires but not strong enough to reset, so maybe something is off with the transformer.
Also I have a transformer for a sys 80a but not sure that they are compatible. In fact I think they are not? Any help would be appreciated.
ok The issue is you are only testing half the voltage. The transformers output VAC as that is what they are receiving on the input side. To get total voltage you have to measure across the pair to lugs for that voltage on the transformer.
One thing to look at with these weird voltages is the fuse blocks. Find the wire that goes to 1 side of the fuse. Measure from the opposite lug on the transformer (see below) to the side of the fuse connected to the other lug. Then switch your lead to the other side of the fuse. If the voltage drops then tarnish on the fise and block has enough resistance to drop the voltage and the fuse holder should be replaced.
Take a look at this image (on page 10): http://arcarc.xmission.com/Pinball/PDF%20Pinball%20Misc/System%201%20Schematics.pdf
to measure ~14VAC off the transformer put your DMM on V AC and test from 3 to 7 on the transformer. 4 to 6 will get you ~11.5. The final voltage you care about on this transformer is 69 VAC from 8 to 9
None of these voltages are DC until they go through the bridge rectifiers.
You can also measure at the A2J1 connector (disconnected from the power supply) Follow these instructions:
Set DMM to VAC
Turn Machine On
Black to Ground
Red to J1 Pin 1 & 2 ~12 VAC each
Red to J1 Pin 4 & 5 ~14 VAC each
Black to J1 Pin 6
Red to J1 Pin 7 ~69 VAC
Turn Machine Off
This transformer won't work for a system 1 based upon the schematics alone. Here's one for a sys 80 https://www.flippers.com/images/Gott-pwr.gif . You get 12 VAC instead of 15 VAC for 3 & 7 but 4 & 6 aren't present. 8 & 9 are present but at 60 VAC and not 69.
Here's the only thread I can find with the question of using a Sys 80 transformer in a Sys 1. It doesn't have a definitive answer.
Good luck. Let me know if you need any more info