Fanuc 6MB fails to power up

[moldmker]

Kitamura MyCenter 2

Fanuc 6MB control

Machine was running fine until waiting at M0 command...then display went blank, tool carousel dropped down and just about every LED on the control panel lit up...except the alarm # output.

Cycle the main power and control powers up but no display on control (CRT is energized but no display) and main relay never energizes.

No LEDS lit on motherboard

Green PIL LED is lit on Input Unit

Green LED is lit on the board that has cables CO1 thru CO5 attached.

I have verified that the Power Unit is outputting +5VC and +24VDC.

Fuses that I could see all checked OK.

Kitamura service indicated that is most likely a dead motherboard.

Any other ideas??

THANKS.

[memoryman]

did you also check the +-15V ?

[moldmker]

No...but I just checked them and they +/- 14.9 vdc

[alexfanuc]

"Green PIL LED is lit on Input Unit" There is also a red led, is it on?

"Green LED is lit on the board that has cables CO1 thru CO5 attached."
Try to disconnect these cables and power on.
Regards
Alex

[moldmker]

Originally Posted by alexfanuc "Green PIL LED is lit on Input Unit" There is also a red led, is it on?

No....green lit only.

Originally Posted by alexfanuc "Green LED is lit on the board that has cables CO1 thru CO5 attached." Try to disconnect these cables and power on. Regards Alex

Will try that tomorrow AM.

Thanks,
Bob

[moldmker]

Alex,
Powered up with C01 thru C05 disconnected...no difference in outcome at all.
Bob

[alexfanuc]

I could be a bad pcb like the CRT/puncher or the memory pcb (Bubble memory). CRT/Puncher pcb is th easiest to swap if you have another machine.
Something else to check: There is a switch in the door. If this switch is open the machine will not power on, just a guess!

[moldmker]

Update: CNC tech has determined that masterboard was indeed faulty since the clock signal was erratic.
Replacement board was sourced and will be here next week.

First question...Just double checking what the tech told me...Is the masterboard a straight forward interchange after making SURE all jumpers match? I have a battery backed up BMU card that should retain all parameters.

Next question...After reviewing the the machine's work order history, I see that Fanuc service installed 2 chips to the old master board to enable additional work offsets. I'm assuming I will need to swap these chips if they are not present on the new board?

Oddly, I have only had 6 fixture offsets available so I suspect the parameter was never enabled.

Last question, I paid a little extra to get a masterboard that matched my rev level exactly....in case this board is DOA... any issues with swapping with a board of an earlier rev level?

Thnks

[fordav11]

the new board will probably come without EPROMs. you need to swap over your EPROMs onto it and hope your EPROMs are not bad.
you probably DO have the extra offsets. 6M usually does not have G54 to G59 by default.

[moldmker]

Thanks for the G54-G59 info.

I have a separate ROM board that contains EPROMs. I see none on the masterboard.

Also, the only other chips that are socketted on the main board are the axis LSI chips which my tech guy said should not need swapped.

I will confirm everthing with him, just trying to educate myself a little.

Thanks

[memoryman]

the masterboard has optional sram chips that also need swapping. We may have a spare 0030 masterboard.

[moldmker]

My masterboard p/n is A20B-0008-0410 / 08D

The only socketted chips I see are as pictured.
The last picture is of the chips that relate to the work coords.