Switching Power Supply issue

[osver]

In my JAMMA cabinet, when hooked up like this:
Jamma Harness --> 3' Jamma extension --> PCB
everything works fine

When I add in the Jammaboards 6-in-1 like this:
Jamma Harness --> 3' Jamma extension --> 6-in-1 PCB --> 3' Jamma extensions --> PCBs
I get a humming noise, games don't run, and it's like there's no power going out of the switcher.

+5 when hooked up to a single board:

+5 when hooked up to the 6-in-1:

Readings were taken at the switcher.

Any clue why it would be so drastically different? I got the same symptoms with two different switchers.

I'm not sure what the issue is, or what to try to fix it.

 

[Womble]

Two options...

1) You have a short somewhere on your chain of boards, disconnect from the PSU and measure the resistance between the 5V and the ground on the 1st board.

2) Your wires between the PSU and the 1st board are too thin and you get massive voltage sag as the current drawn from your chain of boards is too much for the current wires. Basically you need to add more wire, or thicker wire.

 

[Oryk Zinyo]

Something is overloading the power supply. Like Womble said it could be the wiring, but it is more likely something wrong with the switcher. What I would do is disconnect everything then power on the cab checking voltage. Then power it off and put the next component in (it sounds like the extension harness is next). Restore power and check again. Continue to do this until you find the component causing the overload. Then check that component for shorts to the +5v line.

 

[Riptor]

Does that switcher power up all the boards at once(I know some of them do)? Its possible the switcher might be getting overloading and kicking out on you. Remove the boards and try it one board at a time.

 

[Dokert]

Does that switcher power up all the boards at once(I know some of them do)? Its possible the switcher might be getting overloading and kicking out on you. Remove the boards and try it one board at a time.

No, one boardset at a time via switching unit.

 

[osver]

Finally got around to testing it tonight:
PCB hooked straight up, works fine:

Harness > 6-in-1 > Game PCB (so no extensions), nothing, power supply shut down:

Harness > extension > extension > game PCB, works.

So it looks like it's definitely an issue with the 6-in-1 board.

 

[Dokert]

Take a look at what we talked about at norwescon.

 

[osver]

Take a look at what we talked about at norwescon.

I will. I'm just waiting to hear back from jammaboard's CS before I start de-soldering their -5 mod to see if that's the issue. Just in case they want me to send it back and replace it. If that's not an option then I'll do the testing we talked about.

 

[Dokert]

I hope they do the right thing, and replace it for you.