View Full Version : 5151 Monochrome Display

Great Hierophant
October 11th, 2006, 08:39 PM
The 5151 does not have a power switch and is normally plugged into the back of a PC power supply. I assume it can also be plugged into the wall with a suitable cable. However, when you plug it in, the monitor should instantly turn on, emite a high pitched whine and show a lighter screen than when it is truly off, shouldn't it?

October 12th, 2006, 03:49 AM
It sounds like you are trying to determine the serviceability of a 5151.

Yes, you can plug the 5151 into a wall socket with a suitable cable.
As for the other questions, the answer is no. Different models of monitors behave differently.

I don't have the schematic diagram for a 5151, but experiments on my 5151 suggests that it's designed to shut down certain parts of the circuitry if no video signal is detected.
On my 5151, if I have power applied but no video signal, the only sign of life is a faint humming I can hear if I press my ear to the top of the 5151. I can't see the glow of the heaters if I look through the grate in the top of the unit. Turning up the brightness and contract to maximum doesn't show a raster. Even turning of the unit with brightness and contrast at maximum shows nothing.

In a nutshell, the only way to coax any life from a 5151 is to apply both power and a suitable video signal (a monochrome one).

October 12th, 2006, 10:42 AM
I have two 'clone' monochrome monitors , think one is a Samsung,
and they both behave the same way. I thought they were broken until I
actually hooked them up to a monochrome adapter card. :-)
Picture came right up.

nige the hippy
October 12th, 2006, 01:18 PM
Actually, on reading "modem7"'s contribution to this thread, I needn't add much,
On most older monitors, the Hsync input runs the horizontal scan circuitry, which in turn generates the EHT, and usually the heater supply.

The only thing you have to watch out for, especially running the "wrong" monitor on the "wrong" card (as I have done many times in the past, to get a skip-dive monitor running on a home-brew system) is that the wrong frequency Hsync can actually blow the monitor up (as I have done many times in the past too!!!)

October 16th, 2006, 04:35 PM
as Nige points out, this is especially true with the 5151. DON'T plug it into a CGA card. Disaster will ensue...