JAMMA cab power problem

tomtime

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So a few days ago I power up my jamma cab and the monitor wasnt getting any power. I turn it off than back on and nothing has power. I have replaced the power supply, checked fuses, power cord and wall voltages. Everything checked out fine. what should I check next?
 
What fuses did you check? There are fuses near the power cord, possibly near the isolation transformer, inside the power supply, and on the monitor chassis.

What power are you reading at the isolation transformer, what power is present at the switching power supply?
 
The monitor itself might have failed. Check the voltage at the monitor's power connector. If it's good, then chances are, you need to do some monitor work.

What kind of monitor is it?

(I'm going to guess K7000 with a white knob flyback that just went poof.)

-Ian
 
Oh, and I forgot about the safety switches. Are there any white safety switches near the coin door, back door, and any other opening into the cabinet? Have you tried pulling them out until they lock into place?
 
I checked the fuses at the bottom of the cab. Im not sure how to check the iso.

It is in fact a K7000 but a black knob flyback. If the monitor died, wouldnt I still have power to the marquee light?
 
And im not getting any power to the PS which is brand new.

Yeah, you'd get power *to* the PS even if it wasn't installed. You need to figure out where you lost power. Start at where the power cord enters the machine and check voltages, find out where the break is (fuse, interlock, broken wire, corroded terminal).

If you're not getting power, then it's probably not your monitor - I didn't realize you lost all power to the game, I thought you just lost the monitor.

-Ian
 
Could be fuses, could be wiring. With the game unplugged, using continuity test on a DMM, trace the AC feed wires all the way around the cabinet, starting at the prongs of the power cord and working your way inward. At some point you'll find a blown fuse or broken wire, or (rarely) a blown transformer.
 
If there is no power to the power supply then you need to recheck the wiring and input power fuse. Did you check the fuse with a meter?

Also, are you sure the cabinet didn't trip the breaker for the outlet that you are plugging into?
 
Ok, fuses are good and I have continuity everywhere I need it. How can I test the iso transformer? Im scratching my head here...
 
How can I test the iso transformer? Im scratching my head here...

The isolation transformer only powers the monitor. Or, at least, that's how it's supposed to be wired. I've seen a couple miswired games where the power supply was on the isolation transformer too.

Isolation transformer is simple. 120v in, 120v out. Measure at the input side, and the output side.

-Ian
 
OK, so, think this through. You are NOT getting 120v at the switcher. But you ARE getting 120v where the power cord enters the game. That means that somewhere, between where the power cord enters the game, and the power supply, there is a break. We can't do this for you. You are going to have to follow the wires. Something is wrong. Either a broken wire, a blown fuse, bad fuse holder, interlock switch... something. There isn't much in this circuit. I think you need to go back and check. Carefully. Use your meter, don't just eyeball it. Fuses can look good, but be bad. Connections can appear solid, but the wire can be broken inside somewhere.

-Ian
 
I spent most of this afternoon trying to figure this out. I have continuity where it needs to be, replaced the fuse holder and fuses, quadruple checked all ac wires for any signs of damage, checked all connectors and still nothing. Could the line filter be the problem?
 
well since you know how to test Volts AC just follow that wire all the way to the switcher and test the VAC at any point you can.

Post pics of the wire from the line filter to the switcher. and we should be able to help you.
 
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