Could this be wrong ?? (unreg. voltage)
2006-07-24 by gil_we
I experience a very strange phenomenon on my Rolanf MKS-70. Instead of only showing the right text on the VFR screen, all segments lights up, so the text is a bit brighter than the other segments, but still it almost looks like "888888888888888888888888888888888888". I checked what should be the +7V unregulated voltage line with a DMM, and it showed +10.5V when set to read DC, and +23V when set to read AC. Could that be the cause ?? I saw on the schematics that among the lines that go from the assigner board to the display/controlpanel board, two are of the +7V unreg. line, although they do not seem to connect anytwhere.... Any other idea where to check into this ?? I have this problem for about two years now and I'm determined to fix that at last !! The schematics can be found inthe files section, while the display board is on page 26... Thanks all in advance !!