Fadal VMC 4020 electrical problem

Hello all you CNC brains out there, I working on a Fadal VMC 4020 and the problem is that it was working fine one day and the next it wouldn't respond to any keyboard entries. The environment isn't the best, temperature of the shop was in the upper 80's and high humidity. This is what I can tell you, the 1550 board slot1, temp controller board has the bottom lite on, the 1420 video board, slot 7 has a blinking light and slot 8,9,10 and 13 axis controllers have blinking lights. The X,Y and Z driver boards, no lights. the power supply has +5, +12 and -5 volts d.c. "shows no sign of a.c. ripple" Sorry to bug you guys, but I haven't worked on this machine since 2009 and forgot most of what I knew about it. the video information, and I did foul the memory checking for dirty connectors around the memory chips. I have backups for the programs that were in memory. Jerry