Fanuc OM B error 960 NMI ?

[davesnd]

Hi there - I am curently trying to fix a Tong-il machining center with a fanuc 0M B control. When it boots up I get alarm 960 NMI . In the manuals I have it says that this is a problem with the sub cpu board and to replace it. So I bought a replacement from Fanuc USA and installed it, making sure to take the two ROM chips from the old one and put them in the correct sockets on the new one. After doing this I still get alarm 960 when I boot the control. The only difference being that some of the contactors pull in for a second before I get the alarm now, and before they didn't pull in at all. I want to know what NMI stands for and how to trouble shoot this further - the power supply to the board is within specified limits. Neither of the LED's on the sub cpu turn on at any point. The machine was running regularly until about 6 months ago. Then things slowed down and the machine was left off until recently when they tried to turn it on and got this alarm 960 problem. Any ideas or help is greatly appreciated. Thanks.

[fanucman]

nmi is non maskable interrupt..

sounds like a hardware problem.. do you have another machine with the same control?

[davesnd]

Another machine with the same control for what purpose? For parts interchange to trouble shoot? There is a lathe with a 0T control but this 0M is the only CNC mill in the place.