can someone tell me how to test my Williams power brick?

vintagegamer

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can someone tell me how to test my Williams power brick?

I am trying to find out if my power brick is dead for my Williams Moon Patrol. Yesterday I plugged it in with it disconnected from everything, and I got no readings that seemed like it was working. I've never messed with the power bricks though, this is all new to me (note I'm not talking about the linear PS board).

I've done some brief google searches but haven't hit anything yet. Thanks in advance.
 
I'm duping this post from my resto thread bc I don't know how many people are following that one..

Last night I had a little free time, so I decided to tinker with the original Power Brick a bit more. I scrapped the original particle board base (that Mother Nature had actuallly already PRE-scrapped for me), and moved the EMI filter, fuse holder, and transformer to a new plywood base.

I plugged the cord into the wall and, after doing a little further research, was able to check some of the components. 123-124VAC come from the wall outlet up to the EMI filter on the one side, and 123V are heading out of the EMI filter to the molex connector with no problems. I don't have a way yet to check the transformer, because it appears that the power flows back through the wiring to the molex connector pins and that's how power gets to the transformer? This is where I'm lost. At any rate, my last update regarding the Power Brick where I referred to it as 'dead' may have been inaccurate. I could use some suggestions on how to test the transformer or, since I really want to just go with a switcher and adapter at this point, which wires I would be connecting them to in the current Power Brick wiring. I'm guessing the switcher will connect to the 2 wires coming out of the EMI filter?
 
The power flows through the molex connector to the power switch and to the interlock switch. There is also a loopback circuit to make sure there is a wiring harness attached.

If you look on page 12 of the Moon Patrol Drawing package (if you don't have it, a PDF is available from arcarc.xmission.com), you will see that the molex jack/plug combo is wired as:

Jack side
Pin 8 - white-red from line filter
Pin 7 - black-yellow
Pin 3 - yellow goes to primary on transformer (lug 1)
Pin 1 - blue goes to primary on transformer (lug 8)
Pin 6 - yellow comes from lug 1 (part of power loopback)
Pin 4 - blue comes from lug 8 (part of power loopback)
pin 2 - white-yellow goes to lug 5 (part of power loopback)
pin 5 - white-blue goes to lug 4 (part of power loopback)

Pin 9 - black-grey from secondary lug 9 (isolation transformer) for Monitor
Pin 10 - black-grey from secondary lug 10 (isolation transformer) for Monitor
Pin 11 - violet-yellow from secondary lug 9 (isolation transformer) for marquee light
Pin 12 - violet-yellow from secondary lug 10 (isolation transformer) for marquee light

Plug side
Pin 8 - white-red to DPDT Interlock to Blue wire to On/Off switch to white-blue wire
Pin 7 - black-yellow to DPDT Interlock
Pin 3 - black-yellow from DPDT Interlock
Pin 1 - white-blue from On/Off switch
pin 6 - yellow loops back to Pin 2
Pin 2 - yellow loops back to Pin 6
Pin 4 - white loops back to Pin 5
Pin 5 - white loops back to Pin 4

Pin 9 - black-grey (isolation transformer) to Monitor plug
Pin 10 - black-grey (isolation transformer) to Monitor plug
Pin 11 - violet-yellow (isolation transformer) to marquee light
Pin 12 - violet-yellow (isolation transformer) to marquee light

The loopback connections are just there to make sure the circuit is dead without the AC wiring harness attached. So in order to power up the transformer, you will need to get an AC wiring harness or build one. Dockert was making them, I don't know if he has any in stock.

If the above explanation is confusing, go look at the wiring diagram for a while and trace the wires. It should make sense after you have looked at the diagram.

ken
 
Ken thanks so much for taking the time to type all of that up. I really appreciate your attempt to help me out.

I will look at what you have typed and look over the schematic to see what I can figure out.
 
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