Display Netplex Link Down and no LEDs on CPU

[AZviejo]

Hello all,
I turned on my Triple Butterfly Sevens game today, and got a display netplex link down message on the display. looking inside I noticed the CPU board has no lit LEDs. I have 13.5, 6.2 and 24v at the CPU backplane. also removed the power supplies for inspection and nothing looked amiss. No loose connections either. It worked yesterday.

Could anyone lead me in other directions/places/whatever to check before I start thinking of a bad CPU? Any and all help most greatly appreciated!
Mark

[Stayouttadabunker]

That was good that you checked the power voltages on the power connecting Molex on the bottom of the backplane.
It certainly shows that your power supply is fine Mark.

1st off, that may just be an informational message and not really an "error"?

Try checking that 2-wire black/red power harness that runs down to the VFD driver board attached to the back of the door panel.
The driver board is the one with the ribbon cable running up to the VFD display.

You will notice it has a black and red 2-pin harness powering it up.
Disconnect the 2-pin black harness plastic plug by depressing the housing latch inwards to release it from the header socket.
Turn the cabinet's power switch ON, and check with your multimeter the voltage coming out of the harness.

Finally, it's NOT good that the MPU LEDs aren't coming on.
That pretty signifies some sort of possible fatal fault on the MPU.
Why isn't the MPU getting power although your backplane is powered up?
Do you have a 50X series MPU, a 1270 MPU, or 044 version MPU?
Also, certain backplanes have a pair of blue fuses....check those if your backplane has them.
The problem with burnt fuses is that, it takes a short somewhere, to blow one.

[AZviejo]

Fuses were good. 13.3V on the 2 pin connector to the display.
The CPU is a different number than what u mentioned. trying to attach a pic. also one of the daughter board.l
It puzzles me as there are no lit LEDs. I would think even a dead CPU would give some type of a power indications..
Mark

[Stayouttadabunker]

I mentioned that you may have a 1270 MPU in my Reply above.
What you haven't told us ( although it may not matter at this point), is what software you are using.
That may be helpful.
Anything you else you can help us may diagnose what's wrong.

[AZviejo]

I mentioned that you may have a 1270 MPU in my Reply above.
What you haven't told us ( although it may not matter at this point), is what software you are using.
That may be helpful.
Anything you else you can help us may diagnose what's wrong.

Ah! my bad. I didnt realize that 1270 was just the last 4 digits. Sorry about that. Software wise, SB100927, GME 1 and 2 are 363s, Version chip is VS011GX1, and DSP chip says DSPL0002.
I hope thats what you meant for software.
I am totally new to this. Only machine ive owned so forgive my ignorance lol!
Thanks,
Mark

[lookes]

Even without the software mezzanine board installed, a 1270 should have all LED's lit with the red one flashing slowly.

[AZviejo]

Even without the software mezzanine board installed, a 1270 should have all LED's lit with the red one flashing slowly.

I just took another reading at the backplane and the 25V point was 23.94V.
Is that enough of a drop to cut off the CPU board?
Just curious..
Mark

[lookes]

24v is fine. If you are sure the power supply is OK, (Best to try a known good one) then you probably have a fault in the 3.3v supply on the MPU.

[AZviejo]

24v is fine. If you are sure the power supply is OK, (Best to try a known good one) then you probably have a fault in the 3.3v supply on the MPU.

I have no other power supplies to try but a MPU board issue sounds logical.
I have no idea how to check that. there is a burnt spot on the board which was there at C38 when i bought the machine and with that it still worked fine.
I understand you fix 1270 boards? Can I send this off to you? Please let me know how.
Thanks,
Mark

[lookes]

PM Sent.