SOS....Siemens Sinumerik 850M

Hello friends,
You didn't hear from the prussian blue Prussian in Costa Rica for
quite a while. But today I need your H...E...L...P...!!!!!

Mike needs help from somebody who really knows about Siemens CNC
controls. The advice from Siemens Mexico just helped him to make
things worse.

From Mike>
I have a fault on a pair of 1986 or 1987 Siemens Sinumerik 850M.
The four Led's on the operators panel are flashing at about 4 hz and
I have no display. The control was before operating allright. But the
display froze and the 4 led's started flashing. I replaced the
COM/CPU board with another machine. Now I cannot get the both NC's to
start.
HELP

We really appreciate any help.
Best regards,
Sven Peter and Mike Pennington