machine is still whining

[srwebman]

Hi All,
So it turns out it's not the flourescent bulb that's humming in my Heiwa Mahjong Story machine. (See the "welcome to Fabulous Las Vegas" thread for more detail.)

The whine is coming from a circuit board on the inside of the front door just above the reel window. This board is kept safe behind a clear plastic housing.

I am not 100% certain that the whine comes from here, but I'm pretty sure. When I touch the trio of brown/red/orange wires attached to the lower left of this board, the whine changes pitch, but does not go away or decrease in volume. The whine seems to be coming from the circuit board itself, not out through the speakers.

Can someone please tell me what this board does, and if I can make the hum go away myself, or if I need to order a new circuit board.

Thanks,
-Elliott

[luckydog]

are you dure its not a cooling fan??

My Onimusha 3 has a cooling fan on the upper part of the door that runs all the time.

[srwebman]

Pretty sure. It's definitely a board. The whine/hum sounds electrical - not like a motor spinning. Thanks for the suggestion, though.

-Elliott

[birdbrain]

my wife has been whining for 2 months for me to come and get her in michigan

[wibbix]

My guess would be a capacitor.

First, make sure all connections are firmly seated and no wires are loose.

If that didn't help, I would remove the board (observing ESD precautions, of course) and look for bad solder connections or broken/burned components. With the board disconnected, look at the jacks, both on board and on the wiring harness.

With everything connected and the system on, I would carefully touch each cap to see if one of them is 'singing'.

It would be helpful to know what the board is driving, too.

[daverob]

That PCB looks like it's an inverter for the backlight of the LCD screen. It's not that uncommon to find them emitting a high pitched noise, but usually it's not loud enough to cause a problem.

Be _very_ careful if you're prodding around inside the plastic box with the power on. Most fluorescent tubes used for backlighting LCD displays have a strike voltage of around 8000v, so you can get a fair old whack from these inverter boards. Ok the voltage is a fair bit lower when the tube is actually lit, but it's still high enough to give a nasty shock.

[srwebman]

If it's holding all that voltage, then it makes sense that it's covered with a plastic shield.

The tech I spoke to at 5StarDeal says its a sound board, and he's sending me a new one. it occurred to me after I got off the phone with him that the volume control is located in a totally separate place, so I'm guessing it's not a sound board.

at this point, I'm playing a game called "How many times can 5Star send me stuff before they give up and send me a whole new machine?"

I'll keep this thread open until I get the problem resolved.

Thanks,

-Elliott

[new in town]

my wife has been whining for 2 months for me to come and get her in michigan

??? Again we ask in yet another Thread ???

Where ar you?

Spoiler

With WALDO?

[srwebman]

I got my parts yesterday. They sent the entire LCD display which included the board in question. Problem solved. Hooray!

Now if only I can fgure out how to close this thread...