Bill Brooks said: Satellite fwy stations are set for 20 minutes but only runs for a minute, then on to the next. The Nimbus shows a yellow box with an"N", 0 on the monitor screen follows. All other sats are good so bad timing mechanism? Appreciate help !
I'm not sure from your post if you are trying to run heads from the clock or through the clock from the computer. If all of your other satellites are good then the cause is obviously isolated to the clock. It's trying to communicate but isn't. Did you try to do an DMA from the computer? What I would guess is that either your maxi communicate module has gone bad or possibly the face plate. By the sounds of it I'm more inclined to think the face plate. The other thing that can be checked is, are the ribbon cables between the clock, the communication module and then from the communication module to the ROM's are good?
However before you do any of that, did you power down the satellite and wait about 2 minutes? Sometimes that's all it takes. Is the MAXI red light on on the face plate of is it flashing red?