I have an MV40 with a Fanuc 6MB control. My masterboard seems to have shorted somewhere on the -15v rail. Nothing looks obvious and I'm not a whiz with troubleshooting pcb electrics that in depth. The board I have is an A20B-0008-0410 / 05C. Can I use any board with the same first number? For example an A20B-0008-0410 / 07D?
Sorry if this has been asked before, I searched but couldn't find an answer.
Had that board arrive today, but while the overcurrent protection isn't tripping anymore, nothing comes up on the crt screen when powered on. There isn't an alarm shown by the green or red led's on the masterboard either, even with the bubble memory and rom removed. I see proper voltages at the test points. Is there something else I can try before callung it DOA? Also, I presume I should copy the jumper positions from the previous board?
That's my concern, that the new (used) board is doa.
I copied the jumper positions and installed all the daughter boards before powering it up but all I'm getting is a blank screen. I expect to get a memory error on the board's lights with the BMU or other boards removed but nothing is happening at all.
Maybe my best bet is trying to repair my original board. But Im not experienced in that area.
I am in Vancouver, WA. Just across the river from Portland, OR. Board schematics would be handy. I can't easily follow the -15v trace, guessing its more than 2 layers.
Nevermind, only had time to check that masterboard would power without tripping overcurrent protection. Now I've more time, I find that the machine is hanging on bubble read. I can't get the memory to initialize either, I can put in the defect information which is just 000 for both devices on my board, but it also just hangs after inputting the 0 for device 1 and pressing start; it never gets to device 2. I left it for over an hour with no change. So I guess my BMU was taken out with that capacitor? Is there some way to test to be sure it's not still a masterboard problem?
"Then buy a Tulip if yours is bad." Thanks for the endorsement of our products!
Unlikely that the BMU is defective; did you turn on the PWE and FREE MODE switches?
I flipped the free mode switch for the BMU, I haven't had to also flip the write protect switch in the past to initialize the BMU, but will certainly give that a shot. Have another board en route, will also replace that shorted cap and see where things land. Thanks!
BMU was fine, right as always memoryman! Swapped to spare power stabilization unit and we appear to be back in business. Not sure why though, I'm seeing the same levels on each rail for both units, all well within spec. Now have two working BMUs .
Reply with Quote
6MB Replacement Masterboard
.
