Big Blue Voltage...

Altan

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I'm assuming I should have about 110 / 120V if measuring the two connectors on Big Blue.

I'm going to pull up the schematic and look... but figure I'd ask here also.

I'm getting nothing across those two. I do have 110 / 120V coming out of the interlock switch, so I know there is at least some power.

... Altan
 
I'm assuming I should have about 110 / 120V if measuring the two connectors on Big Blue.

I'm going to pull up the schematic and look... but figure I'd ask here also.

I'm getting nothing across those two. I do have 110 / 120V coming out of the interlock switch, so I know there is at least some power.

... Altan

Ok, looked at the schematic. Appears the Big Blue is only after the bridge rectifier, helping with the 10.6 VDC.

Is that right?

I'm going to go back and verify what I'm getting across Big Blue ensuring I'm in DC mode
 
I'm assuming your talking about an Atari game. If that's the case... The original "Big Blue" was 26000uf 15v. That cap is used to smooth out the 10.6v DC from the bridge rectifier (CR1) under the power unit. That is used in the circuit to generate the regulated +5vdc on the ARII board. Set your meter to DC and you'll get about 10v.
 
I'm assuming your talking about an Atari game. If that's the case... The original "Big Blue" was 26000uf 15v. That cap is used to smooth out the 10.6v DC from the bridge rectifier (CR1) under the power unit. That is used in the circuit to generate the regulated +5vdc on the ARII board. Set your meter to DC and you'll get about 10v.

Thanks Brain...

I also realized I wrote something goofy... If I measure across the two connectors on Big Blue I shouldn't get much there... However, if I measure from a Big Blue connector to ground I should get around 10VDC (as you stated).

I should also get around 10VAC (not DC) if I measure F3 to ground also, right?
 
Sorry for the postings that are my streaming thought process.

I measured the transformer side of each fuse connector and got strange results.

F6 to GND, 1.65VAC
F5 to GND, 1.77VAC
F4 to GND, 1.77VAC
F3 to GND, 1.65VAC

This has got to be telling me something... I suppose I should triple check there is 120V going into the transformer.
 
Thanks Brain...

I also realized I wrote something goofy... If I measure across the two connectors on Big Blue I shouldn't get much there... However, if I measure from a Big Blue connector to ground I should get around 10VDC (as you stated).

I should also get around 10VAC (not DC) if I measure F3 to ground also, right?

First, what game are you working on. I'm using my Dig Dug and Centipede schematics to help you. Though the power circuits are identical.

Actually, looking at the schematics, you should get something across the terminals of the Big Blue. Under the metal plate is a bridge rectifier. Big Blue is attached across the + and - of the rectifier CR1. Its purpose is to filter out the "AC ripple" from your rectified 10vdc. If you are not getting 10vdc across Big Blue, your bridge rectifier might be bad.

As far as your strange readings at the fuses... The fuses are protecting the AC windings off the transformer. Metering to ground won't do you any good, your just metering 1 side of an AC signal to a ground un-related to the transformer windings. You have to meter pin to pin on the matched winding pairs. The fuses only protect 1 side of the windings. To get accurate readings you have to either go directly to the transformer or the pins of J5. At J5 there should be sets of wires the same color (except Orange/Violet). Red/Red should be the 36v AC protected by F5. Yellow/Yellow should be 6.1v AC protected by F6.
 
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Thanks again!

First, what game are you working on. I'm using my Dig Dug and Centipede schematics to help you. Though the power circuits are identical.

It's an Asteroids Deluxe

Actually, looking at the schematics, you should get something across the terminals of the Big Blue. Under the metal plate is a bridge rectifier. Big Blue is attached across the + and - of the rectifier CR1. Its purpose is to filter out the "AC ripple" from your rectified 10vdc. If you are not getting 10vdc across Big Blue, your bridge rectifier might be bad.

Turns out I had some problem with the interlock switch not working. Or something in that path.

As far as your strange readings at the fuses... The fuses are protecting the AC windings off the transformer. Metering to ground won't do you any good, your just metering 1 side of an AC signal to a ground un-related to the transformer windings. You have to meter pin to pin on the matched winding pairs. The fuses only protect 1 side of the windings. To get accurate readings you have to either go directly to the transformer or the pins of J5. At J5 there should be sets of wires the same color (except Orange/Violet). Red/Red should be the 36v AC protected by F5. Yellow/Yellow should be 6.1v AC protected by F6.

I clearly need to read up on the theory behind the transformer.

I started a separate thread about "no 5v on an Asteroids Deluxe" about a week ago because I was purchasing one sight unseen and I knew it had that problem. When I realized there was a problem with the interlock switch, I posted some info in that thread (as it wasn't big blue related). Rather than repost here, it would be great if you could take a look at my latest posting here

Thanks again!
 
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